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Colorless, Purple, Rose, ...
Quartz has been known and appreciated since pre-historic times. The most ancient name known is recorded by Theophrastus in about 300-325 BCE, κρύσταλλος or kristallos. The varietal names, rock crystal and bergcrystal, preserve the ancient usage. The root words κρύοσ signifying ice cold and στέλλειυ to contract (or solidify) suggest the ancient belief that kritallos was permanently solidified ice.

The earliest printed use of "querz" was anonymously published in 1505, but attributed to a physician in Freiberg, Germany, Ulrich Rülein von Kalbe (a.k.a. Rülein von Calw, 1527). Agricola used the spelling "quarzum" (Agricola 1530) as well as "querze", but Agricola also referred to "crystallum", "silicum", "silex", and silice". Tomkeieff (1941) suggested an etymology for quartz: "The Saxon miners called large veins - Gänge, and the small cross veins or stringers - Querklüfte. The name ore (Erz, Ertz) was applied to the metallic minerals, the gangue or to the vein material as a whole. In the Erzgebirge, silver ore is frequently found in small cross veins composed of silica. It may be that this ore was called by the Saxon miners 'Querkluftertz' or the cross-vein-ore. Such a clumsy word as 'Querkluftertz' could easily be condensed to 'Querertz' and then to 'Quertz', and eventually become 'Quarz' in German, 'quarzum' in Latin and 'quartz' in English." Tomkeieff (1941, q.v.) noted that "quarz", in its various spellings, was not used by other noted contemporary authors. "Quarz" was used in later literature referring to the Saxony mining district, but seldom elsewhere.

Gradually, there were more references to quartz: E. Brown in 1685 and Johan Gottschalk Wallerius in 1747. In 1669, Nicolaus Steno (Niels Steensen) obliquely formulated the concept of the constancy of interfacial angles in the caption of an illustration of quartz crystals. He referred to them as "cristallus" and "crystallus montium".

Tomkeieff (1941) also noted that Erasmus Bartholinus (1669) used the various spellings for "crystal" to signify other species than quartz and that crystal could refer to other "angulata corpora" (bodies with angles): "In any case in the second half of the XVIIIth century quartz became established as a name of a particular mineral and the name crystal became a generic term synonymous with the old term 'corus angulatum'."
Isostructural with:
Quartz is the most common mineral found on the surface of the Earth. If pure, quartz forms colorless, transparent and very hard crystals with a glass-like luster. A significant component of many igneous, metamorphic and sedimentary rocks, this natural form of silicon dioxide is found in an impressive range of varieties and colours.

Macro- and Cryptocrystalline Quartz

Quartz occurs in two basic forms:

1. The more common macrocrystalline quartz is made of visible crystals or grains. Examples are rock crystals, the grains in sandstone, but also massive quartz that is made of large crystallites without any crystal faces, like vein quartz.

Macrocrystalline Quartz: Smoky Quartz
Macrocrystalline Quartz: Rose Quartz
Macrocrystalline Quartz: Quartz Grains in a Sandstone
Macrocrystalline Quartz: Smoky Quartz
Macrocrystalline Quartz: Rose Quartz
Macrocrystalline Quartz: Quartz Grains in a Sandstone
Macrocrystalline Quartz: Smoky Quartz
Macrocrystalline Quartz: Rose Quartz
Macrocrystalline Quartz: Quartz Grains in a Sandstone
2. Cryptocrystalline quartz or microcrystalline quartz is made of dense and compact aggregates of microscopic quartz crystals and crystallites. Examples are agate and chert. The different types of cryptocrystalline quartz are colloquially subsumed under the term chalcedony, although that term has a more strict definition in scientific literature. It is worth mentioning that most chalcedony contains small amounts of another SiO2 polymorph, moganite, so it is not always pure quartz.

Cryptocrystalline Quartz: Flint
Cryptocrystalline Quartz: Agate
Cryptocrystalline Quartz: Radiolarite Chert
Cryptocrystalline Quartz: Flint
Cryptocrystalline Quartz: Agate
Cryptocrystalline Quartz: Radiolarite Chert
Cryptocrystalline Quartz: Flint
Cryptocrystalline Quartz: Agate
Cryptocrystalline Quartz: Radiolarite Chert

Quartz Varieties

Quartz crystals or aggregates that share certain peculiar physical properties have been classified as quartz varieties with specific "trivial names".
The best known examples are the colored varieties of quartz, like amethyst or smoky quartz, but there are also trivial names for specific crystal shapes, aggregates and textures, like scepter quartz, gwindel or quartzine. Because there are no canonical rules on naming or defining quartz varieties like they are for minerals, the definition of some quartz varieties is precise and generally accepted, while the definition of others varies considerably between different authors, or is rather fuzzy.

Mindat Classification of Quartz Varieties
On Mindat, macrocrystalline quartz and its varieties are listed as quartz and varieties of quartz.
Cryptocrystalline quartz and its varieties are listed as chalcedony, like "Quartz (Var: Chalcedony)", or as variety of chalcedony, like "Chalcedony (Var: Agate)".
More about the specific properties of chalcedony and its varieties can be found at the respective mineral pages.
Note that, contrary to minerals, the definitions of varieties are not mutually exclusive in the sense that no mineral can be another. A single specimen can be correctly classified as several varieties.

Structure of Quartz

Fig.2: Basic structural features of quartz
Fig.1: Threefold helix made of SiO4 groups. The child image is a video.
The structure of quartz was deciphered by Bragg and Gibbs in 1925 (for a review of the structure and symmetry features of quartz, see Heaney, 1994). Its basic building block is the SiO4 group, in which four oxygen atoms surround a central silicon atom to form a tetrahedron. Since each oxygen is member of two SiO4 groups, the formula of quartz is SiO2. The SiO4 tetrahedra form a three-dimensional network and many mineralogy textbooks classify quartz as a network silicate or tectosilicate.

Quartz can be thought of as being made of threefold and sixfold helical chains of SiO4 tetrahedra that run parallel to the c axis. Figure 1 shows two representations of a threefold SiO4 helix and its relationship to the quartz unit cell: to the right a ball model with red oxygen and white silicon atoms, to the left a tetrahedral model, with the corners of the tetrahedra at the position of the oxygen atoms.

Six of such helices are connected to form a ring that surrounds a central channel which runs parallel to the c-axis, sometimes called "c-channel". The SiO4 tetrahedra around the central c-channel form two independent sixfold helices. Figure 2 shows two views of the corresponding structure: looking in the direction of the c-axis in the top row, and looking in the direction of an a-axis in the bottom row. Like quartz crystals, the ring is six-sided but has a trigonal symmetry. The large channels are an important structural feature of quartz because they may be occupied by small cations.

You can explore the crystal structure of quartz with the interactive tool JSmol further down this page.

Handedness of Quartz Crystals

Fig.3: Handedness of Quartz Crystals

A helix is either turning clockwise (right-handed) or counter-clockwise (left-handed). Due to the helical arrangement of the SiO4 tetrahedra, the atomic lattice of quartz possesses the symmetry properties of a helix: Quartz forms left- and right-handed crystals, whose crystal structure and morphology are mirror-images of each other.

In a left-handed crystal with space group P3121, the sixfold helices turn counter-clockwise (left) and the threefold helices clockwise (right).
In a right-handed crystal with space group P3221, the sixfold helices turn clockwise (right) and the threefold helices counter-clockwise (left).
For a thorough review of the symmetry features of quartz, see Heaney (1994).

The crystallographic form of quartz that is characteristic for its symmetry properties is the trigonal trapezohedron, and the position of its faces on the crystal reflect the handedness of the structure of the crystal. The figure to the right visualizes the relationship between the handedness of the six-fold helices and the position of the faces of the trigonal trapezohedron (x - orange) and trigonal bipyramid (s - blue). Unfortunately, these faces are not present on all crystals, and often it is not possible to determine the handedness of a crystal from its morphology.

Quartz is optically active: the polarization of a light ray passing through a crystal parallel to the c-axis will be rotated either to the left or the right, depending on the handedness of the crystal (Arago, 1811; Biot, 1812; Herschel, 1822).

The following table lists how symmetry, morphology and optical behaviour are related:
Space GroupHandedness of
sixfold helix
Handedness of
threefold helix
Indices for
x- and s-forms
Position of
x- and s-face
Rotation of
polarization of light
Left-handed QuartzP3121left (counter-clockwise)right (clockwise)x {6 1 5 1}
s {2 1 1 1}
leftleft (counter-clockwise)
Right-handed QuartzP3221right (clockwise)left (counter-clockwise)x {5 1 6 1}
s {1 1 2 1}
rightright (counter-clockwise)


Quartz is found as individual crystals and as crystal aggregates. Well crystallized quartz crystals are typically six-sided prisms with steep pyramidal terminations. They can be stubby ("short prismatic") or elongated and even needle-like. In most environments quartz crystals are attached to the host rock and only have one tip, but double-terminated crystals are also found.
As a rock-forming mineral quartz commonly occurs as sub-millimeter to centimeter-sized anhedral grains, well-formed crystals are uncommon. Secondary vein-fillings of quartz are typically massive.

Quartz crystals show about 40 different crystallographic forms in nature, but most of the crystals are composed of only a few basic forms that are frequently mentioned in discussions about quartz crystal morphology (Frondel, 1962; Rykart, 1995). It is convenient and common practise to designate them with Latin and Greek letter symbols instead of Miller-Bravais indices. The following figure illustrates the relation of the basic forms (sorted by abundance) to the faces found on quartz crystals. The most common combination of crystallographic forms in quartz crystals is r+m+z.

Fig.4: Basic Crystallographic Forms of Quartz

Fig.5: x and s Face Positions on Left- and Right-handed Crystals
The handedness of quartz crystals can be determined easily from the positions of x faces, which are at the lower left or lower right corner of the r face (orange faces in Fig.5). With some difficulty the handedness can be determined from the position of the s faces (blue faces in Fig.5), which lie between the r and z faces: the s face often shows a fine striation that runs parallel to the edge of the r-face.
The bottom row shows a top view of the crystals. It does not only show their trigonal symmetry but also the chirality of the position of the x faces.

Macroscopic Structure of Quartz Crystals

In response to lattice defects, and apparently reflecting their growth conditions, quartz crystals may develop two very distinct and mutually exclusive types of internal structure:
- Macromosaic Structure, sometimes called "Friedlaender Quartz"
- Lamellar Structure, sometimes called "Bambauer Quartz"

Individual crystals may possess both structural types, but the respective parts of the crystals grew at different developmental stages (Hertweck et al., 1998). It is sometimes claimed that all quartz occurs either as macromosaic or as lamellar structural type. This is not correct.

The lamellar structure was first described by Weil (1931). The crystals contain layers that show an optical anomaly: they are biaxial. The layers are stacked parallel to the crystal faces in an onion-like manner and were found to be associated with a relatively high hydrogen and aluminium content (Bambauer et al., 1961, 1962, 1963). Lamellar quartz cannot be safely recognized without studying the optical properties of the crystal in a thin section.

Macromosaic quartz crystals have been described by Friedlaender (1951) and are composed of slightly tilted and radially arranged wedge-shaped sectors. They are recognized by the presence of sutures on the crystal faces which are often confused with twin boundaries. Crystals with such a structure are found in pegmatite and miarole pockets and in hight-temperature alpine-type fissures.

Quartz Crystal Habits

Fig.6: Common Habits of Quartz Crystals
Strictly speaking, the term "habit" is used to designate the overall shape of individual crystals, regardless of the crystallographic forms (crystal faces) involved. Confusingly, the definitions of some habits of quartz crystals do include specific forms. Many of the trivial names of these habits have been introduced and popularized by rock hounds in the Alps (for a good overview, see Rykart, 1995). The most important habits with trivial names (with synonyms in different languages in braces) are:
a) Normal habit ("Maderaner Habitus", prismatic habit): "typical" quartz crystals that are not or only slightly tapered.
b) Trigonal habit: Crystals with obvious trigonal symmetry, for example, because of missing z faces, or because of a triangular cross section, like in crystals with a Muzo habit (h).
c) Pseudohexagonal habit: Crystals with even development of rhombohedral and prism faces.
d) Cumberland habit: Crystals with very small or absent prism faces, often bipyramidal.
e) Pseudocubic quartz (pseudocubic habit, cubic habit, cube quartz, "Würfelquarz"): Crystals with a dominant r or z form that look like slightly distorted cubes.
f) Dauphiné habit: Crystal tips with a single very dominant rhombohedral face.
g) Tessin habit ("Abito Ticino", "Tessiner Habitus", "Rauriser Habitus", "Penninischer Habitus"): Crystals that are tapered by steep rhombohedral faces { h 0 _i 1 }. At the original locality they possess a macromosaic structure.
h) Muzo habit: Crystals with prism faces that are tapered under the z faces because these are made of a succession of alternating m and z faces, and who have a trigonal cross section at the crystal tips (Gansser, 1963).
Needle quartz (acicular habit): Crystals greatly elongated along the c-axis.

Normal Habit
Dauphiné habit
Tessin habit
Pseudocubic habit
Cumberland habit
Normal Habit
Dauphiné habit
Tessin habit
Pseudocubic habit
Cumberland habit
Normal Habit
Dauphiné habit
Tessin habit
Pseudocubic habit
Cumberland habit

Quartz Growth Forms

In addition to crystallographic forms and habits, many quartz crystals are characterized by peculiar morphological features that reflect different modes of growth during their development. Some of these "growth forms" are found at many different localities and - like habits - have been given "trivial names" (e.g., "cactus quartz", "gwindel"). Some of these are listed as varieties of quartz on Mindat. Among the more common and important growth forms are:
Sceptre quartz: Crystals with syntaxial overgrowth of a second generation tip.
Faden quartz: Crystals and crystal aggregates with a white thread running through the crystals. The thread is caused by repetitive cracking of the crystal during growth and consists of fluid inclusions.
Skeleton or Window or Fenster quartz: Crystals with frame-like, elevated edges of the crystal faces.
Phantom quartz: Crystals in which outlines of the shape of earlier developmental stages of the crystal are visible because of inclusions or color zones.
Sprouting quartz ("Sprossenquarz"): Crystals on which split-growth causes subparallel daughter crystals to sprout from the crystal faces
Artichoke quartz: A form of split-growth resulting in specimens with composite artichoke-like crystal tips.
Gwindel: Crystals elongated and twisted along an a-axis.
Cactus quartz or spirit quartz: Crystals whose prism faces are covered by small, roughly radially grown second-generation crystals.

Scepter quartz
Faden quartz
Cactus quartz
Artichoke quartz
Scepter quartz
Faden quartz
Cactus quartz
Artichoke quartz
Scepter quartz
Faden quartz
Cactus quartz
Artichoke quartz

Quartz Twins

Twinning is very common in quartz, but is often inconspicuous and difficult to recognize. Two types of twinning can be distinguished (data in tables from Jentzsch, 1867, 1868; Gault, 1949; Frondel, 1962):

1. Twins with parallel main crystallographic axes
Twinning AxisTwinning PlaneComposition PlaneTypeHandedness of Domains
Dauphiné Law[0 0 0 1]-{1 0 1 0}Penetration TwinR+R or L+L
Brazil Law-{1 1 2 0}{1 1 2 0}Penetration / Contact TwinL+R
Combined Law[0 0 0 1]{1 1 2 0}-Penetration TwinL+R

Dauphiné and Brazil law twins are very common. Most crystals, even if morphologically untwinned, contain at least small twin domains. Both types of twins can be found in a single crystal.

Dauphiné Law
Fig.7: Dauphiné Law Twin

Also called: Swiss Law, Alpine Law
Dauphiné law twins can be thought of as a merger of two crystals of equal handedness that are rotated by 60° around the c-axis relative to each other (Weiss, 1816, ). They are penetration twins composed of twin domains with irregular boundaries (Leydolt, 1855). The size and shape of the twin domains can vary and the shares of the twin domains in a crystal do not have to be equal. The degree of intergrowth of the domains may increase during growth, starting from roughly triangular sectors at the base to complex irregular patterns at the tip of the crystal (Friedlaender, 1951). Twin domains are only rarely visible in natural crystals and normally need to get visualized by etching the surface or a polished cross section (Leydolt, 1855; Judd, 1888). The photo shows an example of an naturally etched crystal with Dauphiné twin domains. Electronmicroscopical studies reveal that on a small scale the twin domains look like complex polygons with straight boundaries (Lang, 1965; McLaren and Phakey, 1969).

Dauphiné twins can sometimes be recognised by the position and arrangement of crystal faces, in particular the x-faces. Because the rhombohedral faces are composites of r and z faces, they do not show the common size difference of the faces and the crystals assume a pseudohexagonal habit.

Rarely Dauphiné twinned crystals that lack one type of rhombohedral face (either r or z) - and that would display a trigonal habit if they were untwinned - show re-entrant angles at the tip that makes them look like drill heads (for example, Schäfer, 1999).

Dauphiné twins are sometimes called electrical twins, because this kind of twinning reduces or even suppresses the piezoelectricity that is typical for untwinned quartz crystals, while their optical activity remains unaffected (Thomas, 1945; Donnay and Le Page, 1975).

Brazil Law
Fig.8: Brazil Law Twin

Also called: Optical Law
Brazil law twins can be thought of as a merger of a left- and right-handed crystal: they are penetration twins composed of left- and right-handed domains. Their twin boundaries are usually straight lines, resulting in a characteristic pattern made of straight lines and triangles (Leydolt, 1855). As with Dauphiné twins, the twin domains are usually not visible in natural crystals and need to be visualized by etching (Leydolt, 1855). The corresponding surface patterns on crystal faces are polygonal patches with straight boundaries, often triangular.

Brazil law twins that show the ideal arrangement of x and s crystal faces are very rare.

Many amethysts are twinned polysynthetically according to the Brazil Law: Parts of the amethyst crystals, in particular in zones under the r rombohedral faces are composed of alternating layers of left- and right-handed quartz (Brewster 1823; McLaren and Pitkethly, 1982; Taijing and Sunagawa, 1990). The gauge of individual layers is normally less than 1 mm. The layered structure may be visible as a fingerprint-like pattern on rhombohedral faces.

Brazil law twins are sometimes called optical twins, because this kind of twinning reduces or even suppresses the optical activity typical for quartz crystals. Confusingly, and contrary to common belief, Brazil law twinning does also reduce or suppress the piezoelectricity of quartz crystals (Thomas, 1945; Donnay and Le Page, 1975).

Combined Law
Also called: Liebisch Law, Dauphiné-Brazil Law, Leydolt Law
It is not unusual for crystals to show Dauphiné and Brazil law domains in one crystal, and sometimes crystals show x or s faces at positions that would indicate a special type of twinning. However, electron microscopic studies indicate that left- and right-handed domains do not share boundaries when they are rotated with respect to each other (Van Goethem et al., 1977). Accordingly some authors (e.g. Rykart, 1995) do not consider the Liebisch or Combined law to be a true twin law.

2. Twins with inclined main crystallographic axes (incomplete list)
Twinning PlaneComposition PlaneTypeInclination of c-axes
Japan Law{1 1 2 2}{1 1 2 2}Contact Twin84°33'
Zinnwald Law{2 0 2 1}{2 0 2 1}Contact Twin38°13'
Breithaupt Law[1 1 2 1]{1 1 2 1}Contact Twin48°17'
Reichenstein Grieserntal Law{1 0 1 1}{1 0 1 1}Contact Twin76°26'
Fig.9: Twins with Inclined Axes.
a) Japan Law
b) Breithaupt Law
c) Reichenstein-Grieserntal Law
d) Zinnwald Law
Of the twins with inclined main axes, only the Japan law twin is common and well established, while for some of the others (including some that are not listed here) only few specimens, sometimes only one specimen has been reported and the existence of a twin law is questionable. The Reichenstein-Grieserntal Law is sometimes erroneously called "Esterel Law", which is the equivalent for beta-quartz.

Japan Law
Also called: Weiss Law, La Gardette Law
Japan law twins are the only common quartz twins with inclined c axes. The law was first found and described by Weiss (1816) on crystals from La Gardette, France, but the name "Japan law" became more popular after a great number of them were found in Japan. The c-axis of two crystals meet at an angle of 84°33', with two of the m prism faces of both crystals being parallel. The twinning plane {1 1 2 2} of Japan law twins corresponds to the flat negative trigonal bipyramid ξ (the Greek letter xi).
Japan law twins are contact twins (Sunagawa and Yasuda, 1983). The twin junctions often look jagged on the crystal surface, but are perfectly straight in the interior of the crystals, and form a thin plane that runs from the base of the crystal to the V-shaped indentation between the branches (Sunagawa and Yasuda, 1983). Electron microscopic studies revealed that the twin boundary also forms a perfect plane parallel to {1 1 2 2} (Lenart et al. 2012; Momma et al. 2015), but appears to be restricted to the initial growth periods of the crystal, extending only a few hundred micrometers, which has been interpreted as an indication for a formation as a nucleation twin (Lenart et al. 2012). The cause of the twin formation is still not understood.

Most Japan law twins are flattened, and often they are larger than untwinned crystals that accompany them. Depending on the handedness of the two branches of a twin, one can distinguish 8 different basic twinning subtypes that are also twinned according to the Brazil or Dauphiné law (Frondel, 1962), but the pattern of Brazil and Dauphiné twin domains can be very complex (Kozu, 1952).

Right-handed Dauphiné law twin
Left-handed Dauphiné law twin
Typical irregular intergrowth of Dauphiné law twin domains
Dauphiné law twin with re-entrant angles (rare)
Japan law twin
Right-handed Dauphiné law twin
Left-handed Dauphiné law twin
Typical irregular intergrowth of Dauphiné law twin domains
Dauphiné law twin with re-entrant angles (rare)
Japan law twin
Right-handed Dauphiné law twin
Left-handed Dauphiné law twin
Typical irregular intergrowth of Dauphiné law twin domains
Dauphiné law twin with re-entrant angles (rare)
Japan law twin

Colored Quartz Varieties

Compared to many other minerals, quartz is chemically very pure, most crystals contain more than 99.5% SiO2. Nevertheless, varieties colored by impurities occur. These can be devided into two groups:

1. Quartz colored by trace elements built into the crystal lattice.
Only a few elements can replace silicon in the quartz lattice (substitutional positions) or are small enough to occupy free spaces in the lattice (interstitial positions) . In natural quartz crystals, the most common ones to replace Si are Al, Fe, Ge and Ti, whereas Li, Na, Ca, Mg and Fe often occupy interstitial positions in the "c-channels" mentioned under "Structure of Quartz". Of the substitutional trace elements, only Al, Fe and more rarely P are found to play a role in natural colored varieties. There are only a handful of quartz varieties colored by trace elements built into the lattice, sorted by abundance, with the more common ones first:
- Smoky quartz
- Amethyst
- Citrine
- Pink Quartz / Euhedral Rose Quartz
- Prasiolite

With the possible exception of some prasiolites and citrines, the color of these varieties is based on color centers whose formation requires high energy irradiation from radioactive elements in the surrounding rocks (O'Brien, 1955; Lehmann and Moore, 1966; Maschmeyer et al., 1980; Maschmeier and Lehmann, 1983). Quartz varieties based on color-centers are pleochroic, and their color centers can be destroyed by heat treatment.
Note that individual quartz crystals may contain several colored varieties, like an amethyst with smoky zones.

Smoky Quartz
Pink Quartz/Euhedral Rose Quartz
Smoky Quartz
Pink Quartz/Euhedral Rose Quartz
Smoky Quartz
Pink Quartz/Euhedral Rose Quartz

2. Quartz colored by inclusions of separate phases, for example minerals or fluids.
Because quartz crystals grow in many geological environments, they embed many different minerals during growth, and assume the colors of the included minerals. Colors may also be caused by light scattering at finely distributed but colorless inclusions.
There are also trivial names for varieties colored by inclusions that have been found at many localities, like "prase", "ferruginous quartz" or "rose quartz". However, the definitions of these varieties are often rather fuzzy, and different authors use different definitions.

Milky Quartz
Blue Quartz
Ferruginous Quartz
Rose Quartz
Milky Quartz
Blue Quartz
Ferruginous Quartz
Rose Quartz
Milky Quartz
Blue Quartz
Ferruginous Quartz
Rose Quartz


In most cases quartz is easy to identify by its combination of the following properties:
- hardness (easily scratches glass, also harder than steel)
- glass-like luster
- poor to indistinct cleavage
- conchoidal fracture in crystals, in massive specimens the fracture often looks irregular to the naked eye, but still conchoidal at high magnification.

Note that in macrocrystalline quartz the fracture surfaces have a vitreous to resinous luster, whereas in cryptocrystalline quartz (chalcedony) fractured surfaces are dull.

Crystals are very common and their usually six-sided shape and six-sided pyramidal tips are well-known. Intergrown crystals without tips can often be recognized by the presence of the characteristic striation on the prism faces.

Quartz as a rock-forming mineral, in particular as irregular grains in the matrix, occasionally poses problems, and may require additional means of identification. It may be confused with cordierite (pleochroic, tendency to alteration) and nepheline (lower hardness, geological environment incompatible with quartz).

In thin sections macrocrystalline quartz appears clear and homogeneous, with blue-gray to white or bright yellow interference colors and a low relief. Quartz does not show alterations at grain boundaries. Strained quartz grains from metamorphic rocks show a so-called "undulatory extinction" (Blatt and Christie, 1963).

ID Requirements on Mindat

Quartz is one of the few minerals on Mindat where "visual identification" may be accepted as a method of identification for new locentries and photos of well-formed crystals. In other cases, at least hardness should be checked, too.
For quartz as a rock-forming mineral visual identification is often insufficient.

Handling Quartz

Quartz normally does not require special attention when handled or stored. At ambient conditions, quartz is chemically almost inert, so it does not suffer from the problems seen in many other minerals. Crystals do not disintegrate or crumble, they do not oxidize or dissolve easily in water and they don't mind being touched. The only problem for the collector is dust, which will find and cover your crystals, no matter what you do.
Quartz crystals that contain large fluid or gas inclusions may crack when heated - skeleton quartz is the most sensitive variety in this respect - but most quartz specimens can take some heat, like cleaning in warm water, without being damaged.
Quartz is hard, but quite brittle, and with some effort one can damage a crystal even with things that are much softer. The edges of the crystals are very often slightly damaged because crystals were not kept separate from each other.

Colored quartz varieties can pale in sun light, the most sensitive variety is euhedral rose quartz/pink quartz, which should be kept in the dark. Amethyst, smoky quartz and natural citrine will also pale, but it takes very long.

Mild ultrasonic cleaning is usually not a problem as long the crystals are not internally cracked, but some varieties may be damaged, in particular amethyst (due to its polysynthetical Brazil-law twinning) and skeleton quartz with liquid and gas inclusions.

Rock Currier wrote a Mindat article on cleaning quartz that is worthwhile reading:

When cutting, grinding and polishing specimens, keep in mind that quartz dust will cause silicosis (for a review, see Goldsmith, 1994), do not cut or grind dry and wear an appropriate dust mask.

Visit for gemological information about Quartz.

Classification of Quartz

Approved, 'Grandfathered' (first described prior to 1959)

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
Dana 7th ed.:

75 : TECTOSILICATES Si Tetrahedral Frameworks
1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si

7 : Oxides and Hydroxides
8 : Oxides of Si URL:
Please feel free to link to this page.

Occurrences of Quartz

Geological Setting:
Most of them...

Physical Properties of Quartz

Diaphaneity (Transparency):
Transparent, Translucent
Colorless, Purple, Rose, Red, Black, Yellow, Brown, Green, Blue, Orange, etc.
Hardness (Mohs):
Hardness Data:
Mohs hardness reference species
Some variability by direction.
The rhombohedral cleavage r{1011} is most often seen, there are at least six others reported.
Tough when massive
2.65 - 2.66 g/cm3 (Measured)    2.66 g/cm3 (Calculated)

Crystallography of Quartz

Crystal System:
Class (H-M):
3 2 - Trapezohedral
Space Group:
P31 2 1
Cell Parameters:
a = 4.9133Å, c = 5.4053Å
a:c = 1 : 1.1
Unit Cell Volume:
V 113.00 ų (Calculated from Unit Cell)
Dauphiné law.
Brazil law.
Japan law.
Others for beta-quartz...
Space group is P3121 for left-handed crystals and P3221 for right-handed crystals

Crystallographic forms of Quartz

Crystal Atlas:
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Quartz no.5 - Goldschmidt (1913-1926)
Quartz no.7 - Goldschmidt (1913-1926)
Quartz no.9 - Goldschmidt (1913-1926)
Quartz no.10 - Goldschmidt (1913-1926)
Quartz no.12 - Goldschmidt (1913-1926)
Quartz no.23 - Goldschmidt (1913-1926)
Quartz no.35 - Goldschmidt (1913-1926)
Quartz no.46 - Goldschmidt (1913-1926)
Quartz no.47 - Goldschmidt (1913-1926)
Quartz no.96 - Goldschmidt (1913-1926)
Quartz no.121 - Goldschmidt (1913-1926)
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Crystal Structure

Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure Sample: at T = 298 K. European Journal of Mineralogy 2:63-77.

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More Crystal Structures
Click here to view more crystal structures at the American Mineralogist Crystal Structure Database
X-Ray Powder Diffraction:
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Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
X-Ray Powder Diffraction Data:
4.257 (22)
3.342 (100)
2.457 (8)
2.282 (8)
1.8179 (14)
1.5418 (9)
1.3718 (8)

Optical Data of Quartz

Uniaxial (+)
RI values:
nω = 1.543 - 1.545 nε = 1.552 - 1.554
Max Birefringence:
δ = 0.009
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
low, 0.009
Varieties colored by trace elements built into the crystal lattice, as opposed to varieties colored by inclusions, generally show dichroism: smoky quartz, amethyst, citrine, prasiolite, "rose quartz in crystals" (a.k.a. pink quartz), are pleochroic.

Chemical Properties of Quartz

All elements listed in formula:
Common Impurities:

Relationship of Quartz to other Species

4.DA.Carbon Dioxide IceCO2
4.DA.10OpalSiO2 · nH2O
4.DA.25Melanophlogite46SiO2 · 6(N2,CO2) · 2(CH4,N2)
7.8.7Silhydrite3SiO2 · H2O
7.8.8OpalSiO2 · nH2O

Other Names for Quartz

Name in Other Languages:
Bosnian (Latin Script):Kvarc
Irish Gaelic:Grian Cloch
Norwegian (Bokmål):Kvarts
Serbian (Cyrillic Script):Кварц
Simplified Chinese:石英
Slovenian:Kamena strela
Traditional Chinese:石英
Vietnamese:Thạch anh

Other Information

piezoelectric, pyroelectric, may be triboluminescent.
Thermal Behaviour:
Transforms to beta-quartz at 573 deg C and 1 bar (100 kPa) pressure.
Health Risks:
Quartz is usually quite harmless unless broken or powdered. Broken crystals and masses may have razor-sharp edges that can easily cut skin and flesh. Handle with care. Do not grind dry since long-term exposure to finely ground powder may lead to silicosis.
Industrial Uses:
Ore for silicon, glassmaking, frequency standards, optical instruments, silica source for concrete setting, filtering agents as sand. Major component of sand.

References for Quartz

Reference List:
Rülein von Calw, U. (1527) Querz. in: Ein nützlich Bergbüchlin: von allen Metallen / als Golt / Silber / Zcyn / Kupferertz / Eisenstein / Bleyertz / und vom Quecksilber, Loersfelt (Erffurd) 25, 38.

Agricola, G. (1530) Quarzum. in: Bermannus, Sive De Re Metallica, in aedibus Frobenianis (Basileae) 88, 129.

Agricola, G. (1546) Book V. Quartz. in: De Natura Fossilium, Froben (Basileae) 249-275.

Bras-de-Fer, L. (1778) (84) Terre (Élément). in: Explication Morale du Jeu de Cartes; Anecdote Curieuse et Interessante, (Bruxelles), 99-100.

Hoffmann, C.A.S. (1789) Mineralsystem des Herrn Inspektor Werners mit dessen Erlaubnis herausgegeben von C.A.S. Hoffmann. Bergmännisches Journal: 1: 369-398.

Berzelius, J.J. (1810) Zerlegung der Kieselerde durch gewöhnliche chemische Mittel. Annalen der Physik: 36: 89-102. [Discovery of silicon, quartz being made of silicon and oxygen]

Arago, F.J.D. (1811) Mémoire sur une modification remarquable qu'éprouvent les rayons lumineux dans leur passage à travers certains corps diaphanes et sur quelques autres nouveaux phénomènes d'optique. Mémoires de la classe des sciences mathématiques et physiques de l'Institut Impérial de France Année 1811. 1re partie: 92-134. [discovery of optical activity of quartz and of interference colors in polarized light]

Biot, J.B. (1812) Mémoire sur une nouveau genre d'oscillation, que les molecules de la lumiére éprouvent en traversant certains cristeaux. Mémoires de la classe des sciences mathématiques et physiques de l'Institut Impérial de France Année 1812. 1re partie: 1-371.

Weiss, C.S. (1816) Ueber den eigenthümlichen Gang des Krystallisations-systemes beim Quarz, und über eine an ihm neu beobachtete Zwillingskrystallisation. Mitteilungen der Gesellschaft Naturforschender Freunde, Berlin: 7: 163-181. [first description of Dauphiné twin law]

Herschel, J.F.W. (1822) On the rotation impressed by plates of rock crystal on the planes of polarization of the rays of light, as connected with certain peculiarities in its crystallization. Transactions of the Cambridge Philosophical Society: 1: 43-51.

Brewster, D. (1823) On circular polarization, as exhibited in the optical structure of the amethyst, with remarks on the distribution of the colouring matter in that mineral. Transactions of the Royal Society of Edinburgh: 9: 139-152.

Leydolt, F. (1855) Über eine neue Methode, die Structur und Zusammensetzung der Krystalle zu untersuchen, mit besonderer Berücksichtigung der Varietäten des rhomboedrischen Quarzes. Sitzungsberichte der mathematisch naturwissenschaftlichen Classe der kaiserlichen Akademie der Wissenschaften: 15: 59-81.

Rammelsberg, C. (1861) Ueber das Verhalten der aus Kieselsäure bestehenden Mineralien gegen Kalilauge. Annalen der Physik und Chemie: 112: 177-192.

Jenzsch, G. (1867) Ueber die am Quarze vorkommenden sechs Gesetze regelmäßiger Verwachsung mit gekreuzten Hauptaxen. Annalen der Physik: 206: 597-611.

Jenzsch, G. (1868) Ueber die Gesetze regelmäßiger Verwachsung mit gekreuzten Hauptaxen am Quarze. Annalen der Physik: 210: 540-551.

Judd, J.W. (1888) On the development of a lamellar structure in quartz-crystals by mechanical means. The Mineralogical Magazine and Journal of the Mineralogical Society: 8: 1-10.

Meyer, T. (1888) Action of hydrofluoric acid on a sphere of quartz. Proceedings of the Natural Academy of Sciences of Philadelphia: 40: 121.

Fenner, C.N. (1913) The stability relations of the silica minerals. American Journal of Sciences: 36: 331-384.

Zyndel, F. (1913) Über Quarzzwillinge mit nichtparallelen Hauptaxen. Zeitschrift für Krystallographie: 53(1): 15-52.

Adams, S. (1920) A microscopic study of vein quartz. Economic Geology: 15: 623-664.

Weber, L. (1922) Beobachtungen an schweizerischen Bergkristallen. Schweizerische mineralogische und petrographische Mitteilungen: 2: 276-282.

Bragg, W., Gibbs, R.E. (1925) The structure of α and β quartz. Proceedings of the Royal Society of London, Series A: 109(751) 405-427.

Gibbs, R.E. (1926) Structure of α quartz. Proceedings of the Royal Society of London, Series A: 110(754) 443-455.

Hart, G. (1927) The nomenclature of silica. American Mineralogist: 12: 383-395.

Sosman, R.B. (1927) The properties of silica. American Chemical Society, Monograph No.37, 856pp.

Gibson, R.E. (1928) The influence of pressure on the high-low inversion of quartz. Journal of Physical Chemistry: 32: 1197-1205.

Tarr, W.A., Lonsdale, J.T. (1929) Pseudo-cubic quartz crystals from Artesia, New Mexico. American Mineralogist: 14: 50-53.

Tolman, C. (1931) Quartz dikes. American Mineralogist: 16: 278-299.

Weil, R. (1931) Quelques observations concernant la structure du quartz. Compte Rendu 1er Réunion de l'Institut d'Optique: 2-11.

Schubnikow, A., Zinserling, K. (1932) Über die Schlag- und Druckfiguren und über die mechanischen Quarzzwillinge. Zeitschrift für Kristallographie: 74: 243-264.

Drugman, J. (1939) Prismatic cleavage and steep rhombohedral form in α-quartz. Mineralogical Magazine: 25: 259-263.

Koenigsberger, J.G. (1940) Die zentralalpinen Minerallagerstätten. Teil III. Wepf & Co. Verlag, Basel.

Raman, C.V., Nedungadi, T.M.K. (1940) The α-β transition of quartz. Nature: 145: 147.

Tomkeieff, S.I. (1941) Origin of the Name 'Quartz'. Mineralogical Magazine: 26: 172-178.

Frondel, C. (1945) History of the quartz oscillator-plate industry, 1941-1944. American Mineralogist: 30: 205-213.

Frondel, C. (1945) Secondary Dauphiné twinning in quartz. American Mineralogist: 30: 447-460.

Krishnan, R.S. (1945) Raman spectrum of quartz. Nature: 155: 452.

Thomas, L.A. (1945) Terminology of interpenetrating twins in α-quartz. Nature: 155: 424.

Armstrong, E. (1946) Relation between secondary Dauphiné twinning and irradiation-coloring in quartz. American Mineralogist: 31: 456-461.

Baker, G. (1946) Microscopic quartz crystals in brown coal, Victoria. American Mineralogist: 31: 22-30.

Friedman, I.I. (1947) The laboratory growth of quartz. American Mineralogist: 32: 583-588.

Faust, G.T. (1948) Thermal analysis of quartz and its use in calibration in thermal analysis studies. American Mineralogist: 33: 337-345.

Gault, H.R. (1949) The frequency of twin types in quartz crystals. American Mineralogist: 34: 142-162.

Tuttle, O.F. (1949) The variable inversion temperature of quartz as a possible geologic thermometer. American Mineralogist: 34: 723-730.

Chapman, C.A. (1950) Quartz veins formed by metamorphic differentiation of aluminous schists. American Mineralogist: 35: 693-710.

Friedlaender, C. (1951) Untersuchung über die Eignung alpiner Quarze für piezoelektrische Zwecke. Beiträge zur Geologie der Schweiz, Geotechnische Serie, Lieferung 29.

Brown, C.S., Kell, R.C., Thomas, L.A., Wooster, N., Wooster, W.A. (1952) Growth and properties of large crystals of synthetic quartz. Mineralogical Magazine: 29: 858-874.

Kozu, S. (1952) Japanese twins of quartz. American Journal of Science: Bowen Volume Part 1: 281-292.

Van Praagh, G., Willis, B.T.M. (1952) Striations on prism faces of quartz. Nature: 169: 623-624.

Fairbairn, H.W. (1954) The stress-sensitivity of quartz in tectonites. Tschermaks mineralogische und petrographische Mitteilungen: 4: 75-80.

Frederickson, A.F., Cox, J.E. (1954) Mechanism of "solution" of quartz in pure water at elevated temperatures and pressures. American Mineralogist: 39: 886-900.

Frederickson, A.F. (1955) Mosaic structure in quartz. American Mineralogist: 40: 1-9.

O'Brien, M.C.M. (1955) The structure of the colour centres in smoky quartz. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences: 231: 404-414.

Seifert, H. (1955) Über orientierte Abscheidungen von Aminosäuren auf Quarz. Die Naturwissenschaften: 42: 13. [epitaxy of amino acids]

Borg, I. (1956) Note on twinning and pseudo-twinning in detrital quartz grains. American Mineralogist: 41: 792-796.

Krauskopf, K.B. (1956) Dissolution and precipitation of silica at low temperatures. Geochimica et Cosmochimica Acta: 10: 1-26.

Dapples, E.C. (1959) The behavior of silica in diagenesis. in: Ireland, H.A. (editor) Silica in Sediments. A symposium sponsored by the Society of Economic Paleontologists and Mineralogists Society of Economic Paleontologists and Mineralogists, Special Puplication No.7: 36-54.

Denning, R.M., Conrad, M.A. (1959) Directional grinding hardness of quartz by peripheral grinding. American Mineralogist: 44: 423-428.

Krauskopf, K.B. (1959) The geochemistry of silica in sedimentary environments. in: Ireland, H.A. (editor) Silica in Sediments. A symposium sponsored by the Society of Economic Paleontologists and Mineralogists Society of Economic Paleontologists and Mineralogists, Special Puplication No.7: 4-19.

Foster, R.J. (1960) Origin of embayed quartz crystals in acidic volcanic rocks. American Mineralogist: 45: 892-894.

Ballman, A.A. (1961) Growth and properties of colored quartz. American Mineralogist: 46: 439-446.

Bambauer, H.U. (1961) Spurenelementgehalte und -Farbzentren in Quarzen aus Zerrklüften der Schweizer Alpen. Schweizerische mineralogische und petrographische Mitteilungen: 41: 335-369.

Bambauer, H.U., Brunner, G.O., Laves, F. (1961) Beobachtungen über Lamellenbau an Bergkristallen. Zeitschrift für Kristallographie: 116: 173-181.

Bambauer, H.U., Brunner, G.O., Laves, F. (1962) Wasserstoff-Gehalte in Quarzen aus Zerrklüften der Schweizer Alpen und die Deutung ihrer regionalen Abhängigkeit. Schweizerische mineralogische und petrographische Mitteilungen: 42: 221-236.

Frondel, C. (1962) Dana's System of Mineralogy, 7th Edition: Vol. III: Silica Minerals. John Wiley, New York and London.

Bambauer, H.U., Brunner, G.O., Laves, F. (1963) Merkmale des OH-Spektrums alpiner Quarze (3μ-Gebiet). Schweizerische mineralogische und petrographische Mitteilungen: 43: 259-268.

Blatt, H., Christie, J.M. (1963) Undulatory extinction in quartz of igneous and metamorphic rocks and its significance in provenance studies of sedimentary rocks. Journal of Sedimentary Research: 33: 559-579.

Bloss, F.D., Gibbs, G.V. (1963) Cleavage in quartz. American Mineralogist: 48: 821-838.

Gansser, A. (1963) Quarzkristalle aus den kolumbianischen Anden (Südamerika). Schweizerische mineralogische und petrographische Mitteilungen: 43: 91-103.

Lang, A.R. (1965) Mapping Dauphiné and Brazil twins in quartz by X-ray topography. Applied Physics Letters: 7: 168-170.

Dennen, W.H. (1966) Stoichiometric substitution in natural quartz. Geochichimica et Cosmochimica Acta: 30: 1235-1241.

Lehmann, G., Moore, W.J. (1966) Color center in amethyst quartz. Science: 152: 1061-1062.

McLaren, A.C., Retchford, J.A., Griggs, D.T., Christie, J.M. (1967) Transmission electron microscope study of Brazil twins and dislocations experimentally produced in natural quartz. Physica Status Solidi: 19: 631-645.

Carr, R.M. (1968) The problem of quartz-corundum stability. American Mineralogist: 53: 2092-2095.

Carstens, H. (1968) A note on the origin of Brazil twins in lamellar quartz. Norsk Geologiske Tidsskrift: 48: 61-64.

Carstens, H. (1968) The lineage structure of quartz crystals. Contributions to Mineralogy and Petrology: 18: 295-304.

Frondel, C. (1968) Quartz twin on {3032}. Mineralogical Magazine: 36: 861-864.

Bambauer, H.U., Brunner, G.O., Laves, F. (1969) Light scattering of heat-treated quartz in relation to hydrogen-containing defects. American Mineralogist: 54: 718-724.

Kushiro, I. (1969) The system forsterite-diopside-silica with and without water at high pressures. American Journal of Science: 267: 269-294.

McLaren, A.C., Phakey, P.P. (1969) Diffraction contrast from Dauphiné twin boundaries in quartz. Physica Status Solidi: 31: 723-737.

Rice, S.J. (1969) Quartz family minerals. California Division of Mines and Geology Mineral Information Service: 22: 35-38.

Carmichael, I.S.E., Nicholls, J., Smith, A.I. (1970) Silica activity in igneous rocks. American Mineralogist: 55: 246-263.

Feigl, F.J., Anderson, J.H. (1970) Defects in crystalline quartz: electron paramagnetic resonance of E' vacancy centers associated with germanium impurities. Journal of Physics and Chemistry of Solids: 31: 575-596.

Calvert, S.E. (1971) Nature of silica phases in deep sea cherts of the North Atlantic Ocean. Nature Physical Science: 234: 133-134.

Scott, S.D., O'Connor, T.P. (1971) Fluid inclusions in vein quartz, Silverfields Mine, Cobalt, Ontario. The Canadian Mineralogist 11, 263-271.

Bates, J.B., Quist, A.S. (1972) Polarized Raman spectra of β-quartz. The Journal of Chemical Physics: 56: 1528-1533.

Baëta, R.D., Ashbee, K.H.G. (1973) Transmission electron microscopy studies of plastically deformed quartz. Physica Status Solidi A: 18: 155-170.

Gross, G. (1973) Trigonale Symmetrie anzeigende Querstreifung bei Bergkristall. Schweizerische Mineralogische und Petrographische Mitteilungen: 53: 173-183.

Bettermann, P., Liebau, F. (1975) The transformation of amorphous silica to crystalline silica under hydrothermal conditions. Contributions to Mineralogy and Petrology: 53: 25-36.

Donnay, J.D.H., Le Page, Y. (1975) Twin laws versus electrical and optical characters in low quartz. The Canadian Mineralogist: 13: 83-85.

Barron, T.H.K, Huang, C.C., Pasternak, A. (1976) Interatomic forces and lattice dynamics of α-quartz. Journal of Physics C: Solid State Physics: 9: 3925-3940.

Chakraborty, D., Lehmann, G. (1976) Distribution of OH in synthetic and natural quartz crystals. Journal of Solid State Chemistry: 17: 305-311.

Chakraborty, D., Lehmann, G. (1976) On the structures and orientations of hydrogen defects in natural and synthetic quartz crystals. Physica Status Solidi A: 34: 467-474.

Le Page, Y., Donnay, G. (1976) Refinement of the crystal structure of low-quartz. Acta Crystallographica: B32: 2456-2459.

Van Goethem, L., Van Landuyt, J., Amelinckx, S. (1977) The α-β transition in amethyst quartz as studied by electron microscopy and diffraction. The interaction of Dauphiné with Brazil twins. Physica Status Solidi: 41: 129-137.

Flick, H., Weissenbach, N. (1978) Magmatische Würfelquarze in Rhyolithen (Quarzkeratophyren) des Rheinischen Schiefergebirges. Tschermaks Mineralogische und Petrographische Mitteilungen: 25: 117-129.

Robin, P.Y.F. (1979) Theory of metamorphic segregation and related processes. Geochimica et Cosmochimica Acta: 43(10): 1587-1600.

Maschmeyer, D., Niemann, K., Hake, K., Lehmann, G., Räuber, A. (1980) Two modified smoky quartz centres in natural citrine. Physics and Chemistry of Minerals: 6: 145-156.

Flörke, O.W., Mielke, H.G., Weichert, J., Kulke, H. (1981) Quartz with rhombohedral cleavage from Madagascar. American Mineralogist: 66: 596-600.

Sprunt, E.S. (1981) Causes of quartz cathodoluminescence colours. Scanning Electron Microscopy: 525-535.

Wright, A.F., Lehmann, M.S. (1981) The structure of quartz at 25 and 590°C determined by neutron diffraction. Journal of Solid State Chemistry: 36: 371-380.

Bohlen, S.R., Boettcher, A.L. (1982) The quartz-coesite transformation: a precise determination and the effects of other components. Journal of Geophysical Research: 87(B8): 7073-7078.

McLaren, A.C., Pitkethly, D.R. (1982) The twinning microstructure and growth of amethyst quartz. Physics and Chemistry of Minerals: 8: 128-135.

Richet, P., Bottinga, Y., Deniélou, L., Petitet, J.P., Téqui, C. (1982) Thermodynamic properties of quartz, cristobalite, and amorphous SiO2: drop calorimetry measurements between 1000 and 1800 K and a review from 0 to 2000 K. Geochimica et Cosmochmica Acta: 46: 2639-2658.

Serebrennikov, A.J., Valter, A.A., Mashkovtsev, R.I., Scherbakova, M.Ya. (1982) The investigation of defects in shock-metamorphosed quartz. Physics and Chemistry of Minerals: 8: 155-157.

Yasuda, T., Sunagawa, I. (1982) X-ray topographic study of quartz crystals twinned according to japan twin law. Physics and Chemistry of Minerals: 8(3): 121-127.

Maschmeyer, D., Lehmann, G. (1983) A trapped-hole center causing rose coloration of natural quartz. Zeitschrift für Kristallographie: 163: 181-186.

Scandale, E., Stasi, F., Zarka, A. (1983) Growth defects in a Quartz Druse. ac Dislocations. Journal of Applied Crystallography: 16: 39-403.

Sunagawa, I., Yasuda, T. (1983) Apparent re-entrant corner effect upon the morphologies of twinned crystals; a case study of quartz twinned according to Japanese twin law. Journal of Crystal Growth: 65: 43-49.

Barker, C., Robinson, S.J. (1984) Thermal release of water from natural quartz. American Mineralogist: 69: 1078-1081.

Bernhardt, H.-J., Alter, U. (1984) Induced growth striations in quartz crystals. Crystal Research Technology: 19: 453-460.

Rykart, R. (1984) Authigene Quarz-Kristalle. Lapis Mineralien Magazin: 9(6).

Weil, J.A. (1984) A review of electron spin resonance and its applications to the study of paramagnetic defects in crystalline quartz. Physics and Chemistry of Minerals: 10: 149-165.

Scandale, E., Stasi, F. (1985) Growth defects in Quartz Druses. a Pseudo-basal Dislocations. Journal of Applied Crystallography: 18: 275-278.

Bernhardt, H.-J. (1986) A pragmatic model for the simulation of self-induced striations in quartz crystals. Crystal Research Technology: 21: 983-994.

Applin, K.R., Hicks, B.D. (1987) Fibers of dumortierite in quartz. American Mineralogist: 72: 170-172.

Hemingway, B.S. (1987) Quartz: Heat capacities from 340 to 1000 K and revised values for the thermodynamic properties. American Mineralogist: 72: 273-279.

Hurai, V., Stresko, V. (1987) Correlation between quartz crystal morphology and composition of fluid inclusions as infered from fissures in Central Slovakia (Czechoslovakia). Chemical Geology: 61: 225-239.

Jayaraman, A., Wood, D.L., Maines, R.G. (1987) High-pressure Raman study of the vibrational modes in AlPO4 and SiO2 (α-quartz). Physical Review B: 35: 8316-8321.

Molenaar, N., de Jong, A.F.M. (1987) Authigenic quartz and albite in Devonian limestones: origin and significance. Sedimentology: 34: 623-640.

Graziani, G., Lucchesi, S., Scandale, E. (1988) Growth defects and genetic medium of a quartz druse from Traversella,Italy. Neues Jahrbuch für Mineralogie, Abhandlungen: 159: 165-179.

Owen, M.R. (1988) Radiation-damage halos in quartz. Geology: 16: 529-532.

Ramseyer, K., Baumann, J., Matter, A., Mullis, J. (1988) Cathodoluminescence colours of α-quartz. Mineralogical Magazine: 52: 669-677.

Sowa, H. (1988) The oxygen packings of low-quartz and ReO3 under high pressure. Zeitschrift für Kristallographie: 184: 257-268.

Davidson, P.M., Lindsley, D.H. (1989) Thermodynamic analysis of pyroxene-olivine-quartz equilibria in the system CaO-MgO-FeO-SiO2. American Mineralogist: 74: 18-30.

Drees, L.R., Wilding, L.P., Smeck, N.E., Senkayi, A.L. (1989) Silica in soils: quartz and disordered silica polymorphs. in Minerals in Soil Environments, Editor S B Weed. Soil Science Society of America (Madison Wisconsin, USA) 913-974.

Dubrovinskii, L.S., Nozik, Y.Z. (1989) Calculation of the anisotropic thermal parameters of the atoms of α-quartz. Soviet Physics - Doklady: 34: 484-485.

Hazen, R.M. ,Finger, L.W., Hemley, R.J., Mao, H.K. (1989) High-pressure crystal chemistry and amorphization of α-quartz. Solid State Communications: 72: 507-511.

Scandale, E., Stasi, F., Lucchesi, S., Graziani, G. (1989) Growth marks and genetic conditions in a quartz druse. Neues Jahrbuch für Mineralogie, Abhandlungen: 160: 181-192.

Rao, P.S., Weil, J.A., Williams, J.A.S. (1989) EPR investigation of carbonaceous natural quartz single crystals. The Canadian Mineralogist: 27: 219-224.

Blum, A.E., Yund, R.A., Lasaga, A.C. (1990) The effect of dislocation density on the dissolution rate of quartz. Geochimica et Cosmochimica Acta: 54: 283-297.

Brady, P.V., Walther, J.V. (1990) Kinetics of quartz dissolution at low temperature. Chemical Geology: 82: 253-264.

Dove, P.M., Crerar, D.A. (1990) Kinetics of quartz dissolution in electrolyte solutions using a hydrothermal mixed flow reactor. Geochimica et Cosmochimica Acta: 54: 955-969.

Kihara, K. (1990) An X-ray study of the temperature dependence of the quartz structure. European Journal of Mineralogy: 2: 63-77.

Ribet, I., Thiry, M. (1990) Quartz growth in limestone: example from water-table silicification in the Paris Basin. Geochemistry of the Earth's Surface and Mineral Formation. 2nd International Symposium, July 2, 1990, Aix en Provance, France. Chemical Geology: 84: 316-319.

Taijing, L., Sunagawa, I. (1990) Structure of Brazil twin boundaries in amethyst showing brewster fringes. Physics and Chemistry of Minerals: 17: 207-211.

Chernosky, J.V., Berman, R.G. (1991) Experimental reversal of the equilibrium andalusite + calcite + quartz = anorthite + CO2. The Canadian Mineralogist: 29: 791-802.

Cordier, P., Doukhan, J.C. (1991) Water speciation in quartz: A near infrared study. American Mineralogist: 76: 361-369.

Heaney, P.J., Veblen, D.R. (1991) Observations of the alpha-beta phase transition in quartz: A review of imaging and diffraction studies and some new results. American Mineralogist: 76: 1018-1032.

Lüttge, A., Metz, P. (1991) Mechanism and kinetics of the reaction 1 dolomite + 2 quartz = 1 diopside + 2 CO2 investigated by powder experiments. The Canadian Mineralogist: 29: 803-821.

Agrosì, G., Lattanzi, P., Ruggieri, G., Scandale, E. (1992) Growth history of a quartz crystal from growth marks and fluid inclusions data. Neues Jahrbuch für Mineralogie, Monatshefte: 7: 289-294.

Glinnemann, J., King, H.E., Schulz, H., Hahn, T., La Placa, S.J., Dacol, F. (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure. Zeitschrift für Kristallographie: 198: 177-212.

Lentz, D.R., Fowler, A.D. (1992) A dynamic model for graphic quartz-feldspar intergrowths in granitic pegmatites in the southwestern Grenville Province. The Canadian Mineralogist: 30: 571-585.

Peucker-Ehrenbrink, B., Behr, H.-J. (1993) Chemistry of hydrothermal quartz in the post-Variscan "Bavarian Pfahl" system, F.R. Germany. Chemical Geology: 103: 85-102.

Rink, W.J., Rendell, H., Marseglia, E.A., Luff, B.J., Townsend, P.D. (1993) Thermoluminescence spectra of igneous quartz and hydrothermal vein quartz. Physics and Chemistry of Minerals: 20: 353-361.

Berti G.(1994) Microcrystalline properties of quartz by means of XRPD measures. Adv. X-Ray Analysis: 37:359-366.

Cohen, R.E. (1994) First-principles theory of crystalline SiO2. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 369-402.

Cordier, P., Weil, J.A., Howarth, D.F., Doukhan, J.C. (1994) Influence of the (4H)Si defect on dislocation motion in crystalline quartz. European Journal of Mineralogy: 6: 17-22.

Dolino, G., Vallade, M. (1994) Lattice dynamical behavior of anhydrous silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 403-431.

Dove, P.M., Rimstidt, J.D. (1994) Silica-water interactions. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 259-308.

Gibbs, G.V., Downs, J.W., Boisen, M.B. Jr. (1994) The elusive SiO bond. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 331-368.

Goldsmith, D.F. (1994) Health effects of silica dust exposure. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 545-606.

Graetsch, H. (1994) Structural characteristics of opaline and microcrystalline silica minerals. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 209-232.

Heaney, P.J. (1994) Structure and chemistry of the low-pressure silica polymorphs. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 1-40.

Hemley, R.J., Prewitt, C.T., Kingma, K.J. (1994) High-pressure behavior of silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 41-81.

Knauth, L.P. (1994) Petrogenesis of chert. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 233-258.

Kronenberg, A.K. (1994) Hydrogen speciation and chemical weakening of quartz. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 123-176.

Langenhorst, F. (1994) Shock experiments on pre-heated α- and β-quartz: II. X-ray and TEM investigations. Earth and Planetary Science Letters: 128: 683-698.

Navrotsky, A. (1994) Thermochemistry of crystalline and amorphous silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 309-329

Rossman, G.R. (1994) Colored varieties of the silica minerals. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 433-467.

Swamy, V., Saxena, S.K., Sundman, B., Zhang, J. (1994) A thermodynamic assessment of silica phase diagram. Journal of Geophysical Research 99, 11787-11794.

Dong, G., Morrison, G., Jaireth, S. (1995) Quartz textures in epithermal veins, Queensland - classification, origin and implications. Economic Geology: 90: 1841-1856.

Onasch, C.M., Vennemann, T.W. (1995) Disequilibrium partitioning of oxygen isotopes associated with sector zoning in quartz. Geology: 23: 1103-1106.

Rykart, R. (1995) Quarz-Monographie - Die Eigenheiten von Bergkristall, Rauchquarz, Amethyst, Chalcedon, Achat, Opal und anderen Varietäten. Ott-Verlag, Thun.

Stevens Kalceff, M.A., Phillips, M.R. (1995) Cathodoluminescence microcharacterization of the defect structure of quartz. Physics Review: B: 52: 3122-3134.

Gratz, A.J., Fisler, D.K., Bohor, B.F. (1996) Distinguishing shocked from tectonically deformed quartz by the use of the SEM and chemical etching. Earth and Planetary Science Letters: 142: 513-521.

Plötze, M., Wolf, D. (1996) EPR- und TL-Spektren von Quartz: Bestrahlungsabhängigkeit der [TiO4 -/Li +] 0-Zentren. Bericht derJahrestagung der Deutschen Mineralogischen Gesellschaft: 8: 217 (abstr.).

Gaines, R.V., Skinner, C.H>W., Foord, E.E., Mason, B., Rosenzweig, A., King, V.T. (1997) Dana's New Mineralogy : The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, 8th. edition: 1573.

Carpenter, M.A., Salje, E.K.H., Gaeme-Barber, A., Wruck, B., Dove, M.T., Knight, K.S. (1998) Calibration of excess thermodynamic properties and elastic constant variations associated with the α ↔ β phase transition in quartz. American Mineralogist: 83: 2-22.

Gautier, J.-M., Schott, J., Oelkers, E.H. (1998) An experimental study of quartz precipitation and dissolution rates at 200°C. Mineralogical Magazine: 62: 509-510.

Hertweck, B., Beran, A., Niedermayr, G. (1998) IR-spektroskopische Untersuchungen des OH-Gehaltes alpiner Kluftquarze aus österreichischen Vorkommen. Mitteilungen der österreichischen Mineralogischen Gesellschaft: 143: 304-306.

Schäfer, K. (1999) Vogelschnäbel und Sterne - Quarz-Zwillinge: Kristallographische Schätze aus Idar-Oberstein. Lapis Mineralien Magazin: 24(10): 19-26.

Von Goerne, G., Franz, G., Robert, J.L. (1999) Upper thermal stability of tourmaline + quartz in the system MgO–Al2O3–SiO2–B2O3–H2O and Na2O–MgO–Al2O3–SiO2–B2O3–H2O–HCl in hydrothermal solutions and siliceous melts. The Canadian Mineralogist: 37: 1025-1039.

Bachheimer, J.-P. (2000) Comparative NIR and IR examination of natural, synthetic, and irradiated synthetic quartz. European Journal of Mineralogy: 12: 975-986.

Ghent, E.D., Stout, M.Z. (2000) Mineral equilibria in quartz leucoamphibolites (quartz—garnet—plagioclase—hornblende cacl-silicates) from southeastern British Columbia, Canada. The Canadian Mineralogist: 38: 233-244

Bons, P.D. (2001) The formation of large quartz veins by rapid ascent of fluids in mobile hydrofractures. Tectonophysics: 336: 1-17.

Götze, J., Plötze, M., Fuchs, H., Habermann, D. (2001) Origin, spectral characteristics and practical applications of the cathodoluminescence (CL) of quartz - a review. Mineralogy and Petrology: 71: 225-250.

Skála R., Hörz F. (2001) Unit-cell dimensions of experimentally shock-loaded quartz revisited. Meteoritics & Planetary Science: 36: 192-193.

Monger, H.C., Kelly, E.F. (2002) Silica minerals. in Soil Mineralogy with Environmental Applications, Soil Science Society of America (Madison Wisconsin, USA) 611-636.

Hyrsl, J., Niedermayr, G. (2003) Magic World: Inclusions in Quartz / Geheimnisvolle Welt: Einschlüsse in Quarz. Bode Verlag GmbH, Haltern. [in English and German]

Rodgers, K.A., Hampton, W.A. (2003) Laser Raman identification of silica phases comprising microtextural components of sinters. Mineralogical Magazine: 67: 1-13.

Wangen, M., Munz, I.A. (2004) Formation of quartz veins by local dissolution and transport of silica. Chemical Geology: 209: 179-192.

Basile-Doelsch, I., Meunier, J.D., Parron, C. (2005) Another continental pool in the terrestrial silicon cycle. Nature: 433: 399-402.

Botis, S., Nokhrin, S.M., Pan, Y., Xu, Y., Bonli, T. (2005) Natural radiation-induced damage in quartz. I. Correlations between cathodoluminescence colors and paramagnetic defects. The Canadian Mineralogist: 43: 1565-1580.

de Hoog, J.C.M., van Bergen, M.J., Jacobs, M.H.G. (2005) Vapour-phase crystallisation of silica from SiF4-bearing volcanic gases. Annals of Geophysics: 48: 775-785.

Dove, P.M., Han, N., De Yoreo, J.J. (2005) Mechanisms of classical crystal growth theory explain quartz and silicate dissolution behavior. Proceedings of the National Academy of Science: 102: 15357-15362.

Götze, J., Plötze, M., Trautmann, T. (2005) Structure and luminescence characteristics of quartz from pegmatites. American Mineralogist: 90: 13-21.

Choudhury, N., Chaplot, S.L. (2006) Ab initio studies of phonon softening and high-pressure phase transitions of α-quartz SiO2. Physical Review B: 73: 094304-11.

Grimmer, H. (2006) Quartz aggregates revisited. Acta Crystallographica Section A: 62: 103-108.

Enami, M., Nishiyama, T., Mouri, T. (2007) Laser Raman microspectrometry of metamorphic quartz: a simple method for comparison of metamorphic pressures. American Mineralogist: 92: 1303-1315.

Hebert L.B., Rossman G.R. (2008) Greenish quartz found at the Thunder Bay Amethyst Mine Panorama, Thunder Bay, Ontario, Canada. The Canadian Mineralogist: 46: 111-124.

Baur, W.H. (2009) In search of the crystal structure of low quartz. Zeitschrift für Kristallographie: 224: 580-592.

Botis, S.M., Pan, Y. (2009) Theoretical calculations of [AlO4/M+]0 defects in quartz and crystal-chemical controls on the uptake of Al. Mineralogical Magazine: 73: 537-550.

Korsakov, A.V., Perraki, M., Zhukov, V.P., De Gussem, K., Vandenabeele, P., Tomilenko, A.A. (2009) Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets. European Journal of Mineralogy: 21: 1313-1323.

Lehmann, K., Berger, A., Götte, T., Ramseyer, K., Wiedebeck, M. (2009) Growth related zonations in authigenic and hydrothermal quartz characterized by SIMS, EPMA-, SEM-CL- and SEM-CC-imaging. Mineralogical Magazine: 73: 633-643.

Sunagawa, I., Iwasaki, H., Iwasaki, F. (2009) Growth and Morphology of Quartz Crystals: Natural and Synthetic. Terrapub, Tokyo, 201pp.

Thompson, R.M., Downs, R.T. (2010) Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz. American Mineralogist: 95: 104-111.

Wagner, T. Boyce, A.J., Erzinger, J. (2010) Fluid-rock interactions during formation of metamorphic quartz veins: a REE and stable isotope study from the Rhenish Massif, Germany. American Journal of Science: 310: 645-682.

Seifert, W., Rhede, D., Thomas, R., Forster, H.-J., Lucassen, F., Dulski, P., Wirth, R. (2011) Distinctive properties of rock-forming blue quartz: inferences from a multi-analytical study of submicron mineral inclusions. Mineralogical Magazine: 75: 2519-2534.

Götte, T., Ramseyer, K. (2012) Trace element characteristics, luminescence properties and real structure of quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 265-285.

Götze, J. (2012) Classification, mineralogy and industrial potential of SiO2 minerals. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 1-27.

Götze, J. (2012) Mineralogy, geochemistry and cathodoluminescence of authigenic quartz from different sedimentary rocks. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 287-306.

Haus, R., Prinz, S., Priess, C. (2012) Assessment of high purity quartz resources. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 29-51.

Henn, U., Schultz-Guettler, R. (2012) Review of some current coloured quartz varieties. Journal of Gemmology: 33(1-4): 29-43.

Kempe, U., Götze, J., Dombon, E., Monecke, T., Poutivtsev, M. (2012) Quartz regeneration and its use as a repository of genetic information. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 331-355.

Li, Z., Pan, Y. (2012) First-principles calculations of the E'1 center in quartz: structural models, 29Si hyperfine parameters and association with Al impurity. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 161-175.

Müller, A., Wanvik, J.E., Ihlen, P.M. (2012) Petrological and chemical characterization of high-purity quartz deposits with examples from Norway. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 71-118.

Plötze, M., Wolf, D., Krbetschek, M.R. (2012) Gamma-irradiation dependency of EPR and TL-spectral of quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 177-190.

Rusk, B. (2012) Cathodoluminescence textures and trace elements in hydrothermal quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 307-329.

Scholz, R., Chaves, M.L.S.C., Krambrock, K., Pinheiro, M.V.B., Barreto, S.B., de Menezes, M.G. (2012) Brazilian quartz deposits with special emphasis on gemstone quartz and its color treatment. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 139-159.

Deer, W.A., Howie, R.A., Zussman, J. (2013) An introduction to the rock-forming minerals. Mineral Society of Great Britain and Ireland. 510pp.

Pabst, W., Gregorová, E. (2013) Elastic properties of silica polymorphs - a review. Ceramics - Silikáty: 57: 167-184.

Zhang, S., Liu, Y. (2014) Molecular-level mechanisms of quartz dissolution under neutral and alkaline conditions in the presence of electrolytes. Geochemical Journal: 48(2): 189-205.

Eder, S.D., Fladischer, K., Yeandel, S.R., Lelarge, A., Parker, S.C., Søndergård, E., Holst, B. (2015) A giant reconstruction of α-quartz (0001) interpreted as three domains of nano Dauphine twins. Nature, Scientific Reports: 5: 14545. doi: 10.1038/srep14545

Frelinger, S.N., Ledvina, M.D., Kyle, J.R., Zhao, D. (2015) Scanning electron microscopy cathodoluminescence of quartz: Principles, techniques and applications in ore geology. Ore Geology Reviews: 65: 840-852.

Momma, K., Nagase, T., Kuribayashi, T., Kudoh, Y. (2015) Growth history and textures of quartz twinned in accordance with the Japan law. European Journal of Mineralogy: 27: 71-80.

Skalwold, E.A., Bassett, W.A. (2015) Quartz: a bull’s eye on optical activity. Mineralogical Society of America, Chantilly, VA, 16 pages. ISBN 978-0-939950-00-3 [booklet, abstract and free download on the MSA website:]

Skalwold, E.A., Bassett, W.A. (2015) Double trouble: navigating birefringence. Mineralogical Society of America, Chantilly, VA, 20 pages. ISBN 978-0-939950-02-7 [booklet, abstract and free download on the MSA website:]

Calvo, M. (2016) Minerales y Minas de España. Vol VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399pp. [in Spanish]

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Localities for Quartz

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