IMPORTANT MESSAGE. We need your support now to keep mindat.org running. Click here to find out why.
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat Articles
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield Co., Connecticut, USA

This page is currently not sponsored. Click here to sponsor this page.
Key
Lock Map
Latitude & Longitude (WGS84): 41° 41' 50'' North , 73° 4' 5'' West
Latitude & Longitude (decimal): 41.69750,-73.06806
GeoHash:G#: drkj1qc3w
Köppen climate type:Dfb : Warm-summer humid continental climate


With the construction of this dam by the US Army Corps of Engineers following the devastating flood along the Naugatuck River in 1955, the railroad line was moved into a cut along the west side of the dam above the spillway level. At least two workmen died in accidents during the making of this cut (Zodac, 1959). The cut through the Ordovician Ratlum Mountian Schist and some outlier Devonian Nonewaug Granite and pegmatite also exposed numerous hydrothermally mineralized fault zones of unknown origin, but possibly related to Mesozoic rifting. The veins are typically about 0.25 to 1.5 meters thick and contain mostly fluorite, quartz, sulfides (galena, sphalerite, pyrite), calcite and zeolites (stilbite, heulandite, laumontite, harmotome). Other minerals are found in the metamorphic rocks, the pegmatite, or are secondary in origin.

Myer (1962) noted the paragenesis of the hydrothermal minerals in the fault veins as follows:

Hydrothermal mineralization appears to be in four separate stages. Deposition of quartz [and] sphalerite...are the first stage. Quartz cemented the shattered country rock and is the most abundant mineral,...and sphalerite [is] rooted against the quartz. Next, fluorite and calcite, along with galena, [sphalerite], and chalcopyrite, crystallized in a second set of fractures as well as within the quartz-lined cavities. Calcic zeolites, stilbite, heulandite and laumontite, crystallized with calcite in the third stage. They are intergrown and perched on quartz and fluorite druze [sic]. The less siliceous zeolites, [harmotome] and chabazite, are rare and usually found alone on fluorite. The final stage is pyrite in minute crystals that are sprinkled randomly on other minerals.


Collecting is no longer allowed there per US ACOE rules.

There has long been controversy regarding the identification of the brown, generally 6-sided pagoda-like micro-crystals of ZnS found here and generally referred to as wurtzite. This ID was first made by Myer (1962). However, Pete Dunn analyzed crystals via XRD in 1972 (see Yedlin 1973a and b) and obtained "perfect sphalerite patterns". Henderson (1979) showed diagrams of sphalerite crystals "epitaxial" on "wurtzite", and the other way around, with a (0001) (pinacoidal) face of "wurtzite" matching a (111) (tetrahedral) face of sphalerite. Yet (111) is the face that sphalerite twins on. The crystals are actually combined positive and negative tetrahedra of sphalerite twinned on a 6-sided (111) face. Vogt (1991) shows a nice photo of a tetrahedron with a (111) face capping a stack of polysynthetic sphalerite twins resting on multiple sphalerite tetrahedra, but still referring to it as "wurtzite" even though he notes the presence of sphalerite associated with the "wurtzite". Note the re-entrant angles that circumscribe the "prisms" of these pagoda crystals, plus the varying width of the crystals, which are indicative of twinning. Here are some examples of sphalerite tetrahedra with both simple twinning and polysynthetic twinning, some on the same crystal: http://www.mindat.org/photo-783527.html http://www.mindat.org/photo-783535.html and http://www.mindat.org/photo-783519.html The pagoda stacks also cleave along the dodecahedral form {011} and part parallel to the twin plane (111), which is across the "prism" of the stack of twins, whereas wurtzite's best cleavage is prismatic and is not evident here.

A mindat discussion found here http://www.mindat.org/forum.php?read,9,318431,318568#msg-318568 makes an argument that wurtzite is not a separate mineral at all, but merely a sphalerite polytype, while others hold that it is.

Alternative Label Names

This is a list of additional names that have been recorded for mineral labels associated with this locality in the minID database. This may include previous versions of the locality name hierarchy from mindat.org, data entry errors, and it may also include unconfirmed sublocality names or other names that can only be matched to this level.

Thomaston Dam railroad cut, Thomaston, Litchfield Co., Connecticut, USA

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List


60 valid minerals. 6 erroneous literature entries.

Detailed Mineral List:

Actinolite
Formula: ☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Description: In a calc-silicate lens in the schist with intergrown albite, diopside, axinite-(Fe), clinozoisite, titanite, rutile.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Albite
Formula: Na(AlSi3O8)
Habit: granular
Colour: white, greenish
Description: Rock forming constituent of the schists, granite and pegmatite. Rarely as micro-crystals lining Alpine type clefts in schist.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.; Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Albite var: Oligoclase
Formula: (Na,Ca)[Al(Si,Al)Si2O8]
Habit: granular, anhedral
Colour: white to green
Description: The common variety of albite found in local metamorphic rocks. Can be gemmy when very coarse grained.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Almandine
Formula: Fe2+3Al2(SiO4)3
Colour: maroon
Description: An accessory mineral in the schist.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Anatase
Formula: TiO2
Habit: Tabular
Colour: colorless to blue
Description: Microscopic crystals in Alpine cleft type fractures in the schist. Rarely with brookite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.; Henderson, William A. (1995), Microminerals of Connecticut; Rocks & Minerals: 70: 420-425.
Anglesite ?
Formula: PbSO4
Description: Included in a list by the reference with no supporting details. Presumably an alteration of galena, though in Connecticut cerussite is the more common alteration.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Annite
Formula: KFe2+3(AlSi3O10)(OH)2
Habit: micaceous
Colour: black to brownish-black
Description: Commonly found as an accessory mineral in the schist, also found as brownish-black plates up to two inches in size in the granite pegmatite. Vogt
Reference: Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
'Apophyllite'
Habit: tabular to pyramidal
Colour: off-white to yellow
Description: In hydrothermal fault veins with chabazite, stilbite, quartz, pyrite, and calcite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Aragonite ?
Formula: CaCO3
Description: Included in a list with a question mark by the primary reference. Latter lists do not include a question mark, but provide no supporting details.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Autunite ?
Formula: Ca(UO2)2(PO4)2 · 11H2O
Description: Included in lists with no supporting information. No other primary or secondary U minerals are known from here, its detection may have been based on green UV fluorescence, possibly mistaken for the much more common opal-AN.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Axinite-(Fe)
Formula: Ca2Fe2+Al2BSi4O15OH
Habit: "small plates and confused aggregates" (Schooner, 1961)
Colour: pale lavender
Description: Intergrown with albite, diopside, actinolite, clinozoisite, and titanite w/accessory rutile, apparently from a calc-silicate lens in the schist. Schooner (1961) reports that some excellent specimens were obtained.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.; Weber, Marcelle H. and Earle C. Sullivan. (1995), Connecticut Mineral Locality Index. Rocks & Minerals (Connecticut Issue): 70(6): 401.
Baryte
Formula: BaSO4
Habit: tabular
Colour: white
Fluorescence: bright yellow, cream under SW UV
Description: Mostly it is found massive, but it also occurs in crystals up to one-half inch or more. May be confused with calcite, which occurs here as very thin tabular white crystals that mimic barite. Vogt describes baryte as "thin, white tabular crystals from a quarter inch to two inches across. While some of the barite fluoresces a cream color under shortwave ultraviolet light, other appears to be a salmon-pink." The latter is color is typical of calcite fluorescence. However, Vogt also states: "A bright yellow fluorescence of barite was observed when small crystals of honey-colored calcite were in close proximity to the barite. Some unusual forms of pyrite can be found in between the barite platelets. The mineral occurs associated with calcite, fluorite, galena, pyrite, quartz, sphalerite". Use acid to differentiate baryte from tabular calcite here.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Beryl ?
Formula: Be3Al2(Si6O18)
Description: Included in species lists with no supporting information. Possibly occurs in the pegmatite at the cut, but no documented specimens.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Brookite
Formula: TiO2
Description: Occurs in Alpine clefts in the schist with anatase.
Reference: Henderson, William A. (1995), Microminerals of Connecticut; Rocks & Minerals: 70(6): 420-425.
Calcite
Formula: CaCO3
Habit: scalenohedral, hexagonal tabular, rhombohedral
Colour: white, cream, honey
Fluorescence: bright orange-red, rose, yellow under SW UV, commonly better under MW UV. Yellow crystals also phosphorescent.
Description: As scalenohedron crystals, some are doubly terminated, up to one inch. Micro-sized rhombohedral crystals in a quartz vug. But most obvious as very thin white tabular crystals commonly confused with baryte (use acid to tell), usually associated with stilbite and fluorite. "Each plate is dominated by the basal pinacoid (0001) and modified by a rhombohedron, and many plates form a striking pagoda-like stack with the c-axis in optical continuity within the succession. As many as 20 consecutive plates can be in a stack.", Myer. Also as cleavable masses with fluorite and sphalerite.
Reference: Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.; Myer, George H. (1962), Hydrothermal Wurtzite at Thomaston Dam, Connecticut. American Mineralogist: 47(7-8): 977-979.; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Cerussite
Formula: PbCO3
Description: Alteration crust on galena. Small crystals.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.; Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
'Chabazite'
Description: good microcrystals can be found together with other zeolites
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Chalcopyrite
Formula: CuFeS2
Colour: brassy-yellow
Description: Small masses with sphalerite in schist-hosted hydrothemal fault veins.
Reference: Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
'Chlorite Group'
Habit: plates, spherical aggregates
Colour: tan
Description: As micro plates, tan-colored aggregates, and rounded, fuzzy little spheres. It is found associated with barite, calcite, and quartz. Also as a retrograde metamorphic mineral in the schist.
Reference: Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Clinozoisite
Formula: {Ca2}{Al3}(Si2O7)(SiO4)O(OH)
Description: In a calc-silicate lens in the schist with intergrown albite, actinolite, axinite-(Fe), diopside, titanite, rutile.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Copiapite
Formula: Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
Colour: yellow-green
Description: Encrustations from the weathering of pyrite and pyrrhotite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Datolite
Formula: CaB(SiO4)(OH)
Description: According to Segeler & Molon (1985) found in trap rock ballast placed along the railroad tracks, so not really from this locality.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Diopside
Formula: CaMgSi2O6
Colour: pale to emerald green
Description: In a calc-silicate lens in the schist with intergrown albite, actinolite, axinite-(Fe), clinozoisite, titanite, rutile. Schooner (1961) reports collecting specimens containing small emerald-green areas.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Epidote
Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Description: Included in species lists without any supporting data, but it is very common in the state and plausible for the metamorphic geology of the area.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Fluorapatite
Formula: Ca5(PO4)3F
Fluorescence: yellow under SW UV
Description: Accessory mineral in the schist and pegmatite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Fluorite
Formula: CaF2
Habit: cubic, sometimes modified by dodecahedron and tetrahexahedron
Colour: purple and green shades to colorless, usually in layers
Fluorescence: blue-white to purplish blue under SW UV, often zoned with the daylight color.
Description: Very common in hydrothermal fault veins as coarse crystalline masses, found with most minerals present in these veins: quartz, calcite, galena, sphalerite, pyrite, zeolites, with open spaces lined by tightly packed, rough-surfaced (from many small sub-faces) crystals. Crystals to 7 cm were removed intact during the initial blasting of the railroad cut. As well-formed euhedral isolated crystals in voids with other minerals usually up to 2 cm.
Reference: Fluorite: The Collector's Choice. Extra Lapis English No. 9; Rocks & Minerals (1995) 70:396-409; Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Galena
Formula: PbS
Habit: cubic, octahedra rare
Colour: metallic gray
Description: Common as cleavable masses in the hydrothermal fault veins with fluorite, quartz, calcite, sphalerite, zeolites, etc. Crystals in open spaces typically range in size to about 5 cm, but a 7 kg galena crystal (10 cm on a side) was reportedly found by a workman at the site. Some <0.5 cm octahedra were also found.
Reference: Fluorite: The Collector's Choice. Extra Lapis English No. 9; Rocks & Minerals (1995) 70:396-409; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.; Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Goethite
Formula: α-Fe3+O(OH)
Colour: brown
Description: Common weathering product.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Graphite
Formula: C
Colour: dark gray
Description: A generally inconspicuous accessory mineral in the schist. Most obvious when the rock is coarse grained.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Greenockite ?
Formula: CdS
Colour: yellow
Description: Though reportedly occurring with sphalerite at several Connecticut localities, these reports appear to be based solely on the yellow color. While plausible, they lack analytical confirmation; both chemical and structural to differentiate it from similar appearing, dimorphous hawleyite. Schooner (1961) claims greenockite rarely forms intergrowths with sphalerite here.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Grossular
Formula: Ca3Al2(SiO4)3
Description: A component of local calc-silicate lenses in the schist.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Harmotome
Formula: (Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Habit: Cruciform Marburg twins, with or without re-entrants, or simpler Morvenite twins.
Colour: white
Description: White crystals to about 1 cm, commonly dusted with micro-pyrites. This zeolite has the same morphology as phillipsite, but according to Tschernich's 1992 "Zeolites of the World", harmotome is typical of lead deposits whereas phillipsite occurs in volcanics. This locality is thus favorable for harmotome. Henderson (1979) analyzed crystals and found that "...microprobe analysis shows the Ba:Si ratio to be 1.2:6, and the amounts of K, Na and Ca to be low. This data fits harmotome perfectly, and is not consistent with either phillipsite or wellsite."
Reference: Henderson, William A. (1979), Microminerals. Thomaston Dam. Mineralogical Record: 10: 239-241.
Hemimorphite
Formula: Zn4Si2O7(OH)2 · H2O
Habit: hemispherical aggregates of radiating needles or thin blades
Colour: white
Description: As tiny white balls (1 - 2 mm) on fluorite. The balls appeared to be in radiating needles or thin blades. Erroneously reported by some as pectolite.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
'Heulandite subgroup'
Habit: coffin-shaped
Colour: colorless to pale yellow or tan
Description: Common in the hydrothermal fault veins with quartz, sphalerite, pyrite, galena. Pearly, translucent crystals usually <1 cm, but rarely up to 2.5 cm.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
'Hornblende'
Habit: anhedral to subhedral elongated prisms
Colour: very dark green to black
Description: A component of local amphibolite lenses in the schist. More specifically, it is probably common magnesio-hornblende.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Hydrozincite
Formula: Zn5(CO3)2(OH)6
Habit: colloform crusts
Colour: white
Fluorescence: blue-white
Description: Colloform white crusts on schist collected by Ronald Januzzi.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Ilmenite
Formula: Fe2+TiO3
Habit: subhedral tabular
Colour: black
Description: Accessory mineral in the schist, especially in quart-rich segregations with kyanite.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.; Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Jarosite ?
Formula: KFe3+ 3(SO4)2(OH)6
Description: Included by the reference in a list of species, with a question mark and no supporting details.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Kaolinite ?
Formula: Al2(Si2O5)(OH)4
Colour: white
Description: A mass of white clay occurs in a fault that cuts the pegmatite, with material constantly sliding out onto the track. Presumed to be kaolinite, but unanalyzed. Associated with pinkish montmorillonite.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Kyanite
Formula: Al2(SiO4)O
Habit: bladed
Colour: pale to sky blue
Description: Crystalline masses in the host schist, commonly heavily rust-stained and hard to recognize. Crystals can exceed 10 cm. It fluoresces a weak pink-red under longwave UV (Don Swenson).
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Laumontite
Formula: CaAl2Si4O12 · 4H2O
Reference: Januzzi, 1976. Mineral Localities of Connecticut and Southeastern New York State (Taylor Assoc./Mineralogical Press); Rocks & Minerals (1985) 60:119-124
'Limonite'
Formula: (Fe,O,OH,H2O)
Colour: rusty brown
Description: Common weathering product staining rocks and minerals.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Magnetite
Formula: Fe2+Fe3+2O4
Description: An accessory mineral in the schist.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Malachite ?
Formula: Cu2(CO3)(OH)2
Colour: green
Description: A typical alteration of chalcopyrite. Included in a list of species with a question mark and no supporting details.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Melanterite
Formula: Fe2+(H2O)6SO4 · H2O
Description: Common weathering product of pyrite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Microcline
Formula: K(AlSi3O8)
Habit: cleavable masses, subhedral
Colour: white
Description: A constituent of the pegmatites.
Reference: Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Montmorillonite ?
Formula: (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Colour: pink
Description: A visual ID based on color, clay texture and association with probably kaolinite in the "slide" fault zone that cuts the pegmatite.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Mordenite ?
Formula: (Na2,Ca,K2)Al2Si10O24 · 7H2O
Description: Included in a list of species with no supporting documentation, except for an "unconfirmed" footnote.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Habit: anhedral flakes in schist
Colour: silvery-white
Description: Major constituent of the schist, and an accessory up to 5 cm in the pegmatites and granite.
Reference: Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Muscovite var: Sericite
Formula: KAl2(AlSi3O10)(OH)2
Colour: pale green
Description: Fine-grained soft layers filling seams in pegmatite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Natrolite
Formula: Na2Al2Si3O10 · 2H2O
Description: According to Segeler & Molon (1985) found in trap rock ballast placed along the railroad tracks, so not really from this locality.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Opal
Formula: SiO2 · nH2O
Habit: encrustations
Colour: colorless to milky white
Fluorescence: green under LW and SW UV
Description: Very common as thin to slightly botryoidal, transparent to milky encrustations usually on visible under UV light.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Opal var: Opal-AN
Formula: SiO2 · nH2O
Habit: encrustations
Colour: colorless to milky white
Fluorescence: green under LW and SW UV
Description: Very common as thin to slightly botryoidal, transparent to milky encrustations usually on visible under UV light.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
'Phillipsite'
Description: This zeolite has the same morphology as harmotome, but according to Tschernich's 1992 "Zeolites of the World", harmotome is typical of lead deposits whereas phillipsite occurs in volcanics. This locality is thus favorable for harmotome. Henderson (1979) analyzed crystals and found that "...microprobe analysis shows the Ba:Si ratio to be 1.2:6, and the amounts of K, Na and Ca to be low. This data fits harmotome perfectly, and is not consistent with either phillipsite or wellsite."
Reference: Henderson, William A. (1979), Microminerals. Thomaston Dam. Mineralogical Record: 10: 239-241.
Phlogopite
Formula: KMg3(AlSi3O10)(OH)2
Description: Described by Vogt (1991) as brown mica in pegmatite, but much muscovite or annite can appear brown and Mg is very scarce in pegmatites.
Reference: Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Prehnite
Formula: Ca2Al2Si3O10(OH)2
Description: According to Segeler & Molon (1985) found in trap rock ballast placed along the railroad tracks, so not really from this locality.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Pyrite
Formula: FeS2
Habit: cubic, pyritohedral, octahedral, unusual elongated forms. Penetration twins.
Colour: brass-yellow, sometimes iridescent or with a reddish-brown coating.
Description: Crystals generally very small <2mm, but typically well formed and complex, associated with barite, galena, quartz, sphalerite, stilbite, heulandite. Twinned crystals are very common. Some repeated twins have been found >1 cm. Pyrite aggregates may mimic marcasite crystal groups with rather typical curved faces. Under the microscope they appear as aggregates of small cubes.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.; Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Pyrolusite ?
Formula: Mn4+O2
Description: A black earthy mineral which has not been properly identified.
Reference: Januzzi, 1976. Mineral Localities of Connecticut and Southeastern New York State (Taylor Assoc./Mineralogical Press); Rocks & Minerals (1985) 60:119-124
Pyromorphite
Formula: Pb5(PO4)3Cl
Habit: radiating groups of elongated prismatic
Colour: green
Description: Fine green crystals, some of which comprise radiating groups. Schooner (1961) describes "beautiful specimens...These are equally small, compared with pyromorphite from classical localities, but they are clean and quite attractive. Some show the mineral, associated with wulfenite crystals, in vugs of pegmatite, near ore veins; others have pyromorphite filling seams in green and purple fluorite."
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Pyrrhotite
Formula: Fe7S8
Habit: anhedral
Colour: bronzy, usually tarnished nearly black
Description: Accessory mineral in quartz segregations in the schist, can be associated with kyanite.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Quartz
Formula: SiO2
Habit: massive in schist, pegmatite and granite. Elongated prismatic in hydrothermal veins, typically as a druse lining open spaces. Dauphine and Japan-law twins, bowtie aggregates.
Colour: colorless, milky, pale smoky
Description: Crystals usually as a druse, rarely >2.5 cm. Several crystals were found to be translucent, milky white from the base to about three quarters of the height, with the tip becoming completely transparent towards its termination. Associated in the hydrothermal veins with barite, calcite, fluorite, galena, pyrite, sphalerite, and zeolites.
Reference: Fluorite: The Collector's Choice. Extra Lapis English No. 9; Rocks & Minerals (1985) 60:119-124; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.; Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Quartz var: Smoky Quartz
Formula: SiO2
Reference: Rocks & Minerals (1985) 60:119-124
Rutile
Formula: TiO2
Description: In a calc-silicate lens in the schist with intergrown albite, actinolite, axinite-(Fe), diopside, titanite, clinozoisite.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Schorl
Formula: Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3(OH)
Habit: subhedral elongated prismatic
Colour: black
Description: Can be an accessory mineral in the pegmatite or schist.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Sillimanite
Formula: Al2(SiO4)O
Habit: Fibrous
Description: Accessory mineral in schist.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Smithsonite ?
Formula: ZnCO3
Description: Included in a list of species with no supporting data and a question mark. Presumably an alteration of sphalerite, but hydrozincite is much more common locally.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Sphalerite
Formula: ZnS
Habit: pagoda-like polysynthetic twins on (111) resulting in pseudo-hexagonal "prisms" with re-entrant striae
Colour: dark reddish-brown, dark brown, black
Description: In hydrothermal fault veins associated with barite, calcite, fluorite, galena, pyrite, quartz, and zeolites. Pete Dunn analyzed crystals in 1973: “It has been said that the wurtzite from Thomaston Dam, Connecticut, was of a type that changed to sphalerite under the crushing necessary for a powder x-ray photo. This thought intrigued me and I checked it out by taking a regular powder photo after crushing the sample in the usual fashion, and then took another x-ray using the Gandolfi camera which gives powder photos from single crystals. Result — both photos perfect sphalerite patterns, and identical" (Yedlin, 1973a). Henderson (1979) showed diagrams of sphalerite crystals epitaxial on supposed wurtzite, and the other way around, with a (0001) (pinacoidal) face of "wurtzite" matching a (111) (tetrahedral) face of sphalerite. In any case, the crystals from this locality, commonly labeled "wurtzite" appear to be polysynthetically twinning, combined positive and negative tetrahedra of sphalerite on a 6-sided (111) face. Note the re-entrant angles that circumscribe the "prisms" of these crystals, which are indicative of twinning.
Reference: Yedlin, Neal. (1973a), Yedlin on Micromounting. Mineralogical Record: 4(2).; Yedlin, Neal. (1973b), Yedlin on Micromounting. Mineralogical Record: 4(6).; Fluorite: The Collector's Choice. Extra Lapis English No. 9; Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Henderson, William A. (1995), Microminerals of Connecticut; Rocks & Minerals: 70: 420-425.; Henderson, William A. (1979), Microminerals. Thomaston Dam. Mineralogical Record: 10: 239-241.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Staurolite
Formula: Fe2+2Al9Si4O23(OH)
Colour: brown
Description: An accessory mineral in the schist.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Stilbite-Ca
Formula: NaCa4[Al9Si27O72] · nH2O
Reference: No reference listed
'Stilbite subgroup'
Habit: divergent fan-like to bow-tie aggregates of bladed, tabular crystals with pointed terminations
Colour: white to creamy yellow
Description: Crystal aggregates to about 2.5 cm associated with barite, calcite, pyrite, quartz, sphalerite, and fluorite. Some of the best Connecticut stilbite was found here sometimes richly mineralized in voids in hydrothermal veins and fractures, covering other hydrothermal minerals or on schist, pegmatite or granite.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.; Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.; Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Stilpnomelane ?
Formula: (K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
Description: Included in a list of species with a question mark and no supporting data.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Sulphur ?
Formula: S8
Description: Included in a list of species with a question mark and no supporting data. Possibly confusion with copiapite.
Reference: Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Titanite
Formula: CaTi(SiO4)O
Colour: yellow and light brownish
Description: In a calc-silicate lens in the schist with intergrown albite, actinolite, axinite-(Fe), diopside, clinozoisite, rutile.
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Vanadinite ?
Formula: Pb5(VO4)3Cl
Description: "In the [Marcelle and Charles] Weber collection, the author saw a specimen of oxidized metallic minerals, from the Thomaston Dam railroad cut, containing tiny brown prisms of what may be the endlichite variety of this mineral. This remains in the problematical category." Schooner (1961)
Reference: Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Wulfenite
Formula: Pb(MoO4)
Habit: peudocubic, bipyramidal
Colour: orange-red
Description: "Here and there small microscopic wulfenites occur both as pseudocubic (similar to the Loudville, Massachusetts, material only considerably smaller) as well as bipyramidal crystals (Marcelle Weber, personal communication, 1984)." (Segeler & Molon, 1985). At least one former Ron Januzzi specimen of a platy orange mineral in crude micro-crystals turned out to be calcite.
Reference: Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Wurtzite
Formula: (Zn,Fe)S
Description: Erroneously reported by Myer (1962) and refuted by XRD analyses by Pete Dunn (Yedlin, 1973a) showing "perfect sphalerite patterns". Pseudo-hexagonal crystals are polysynthetically twinned sphalerite positive and negative tetrahedra.
Reference: Myer, George H. (1962), Hydrothermal Wurtzite at Thomaston Dam, Connecticut. American Mineralogist: 47(7-8): 977-979.; Yedlin, Neal. (1973a), Yedlin on Micromounting. Mineralogical Record: 4(2).
Zircon
Formula: Zr(SiO4)
Fluorescence: orange-yellow
Description: Microscopic accessory in the pegmatites.
Reference: Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
'Graphite'1.CB.05aC
Sulphur ?1.CC.05S8
Group 2 - Sulphides and Sulfosalts
'Chalcopyrite'2.CB.10aCuFeS2
'Galena'2.CD.10PbS
'Greenockite' ?2.CB.45CdS
Pyrite2.EB.05aFeS2
Pyrrhotite2.CC.10Fe7S8
Sphalerite2.CB.05aZnS
Wurtzite ?2.CB.45(Zn,Fe)S
Group 3 - Halides
'Fluorite'3.AB.25CaF2
Group 4 - Oxides and Hydroxides
'Anatase'4.DD.05TiO2
'Brookite'4.DD.10TiO2
'Goethite'4.00.α-Fe3+O(OH)
'Ilmenite'4.CB.05Fe2+TiO3
'Magnetite'4.BB.05Fe2+Fe3+2O4
Opal4.DA.10SiO2 · nH2O
var: Opal-AN4.DA.10SiO2 · nH2O
Pyrolusite ?4.DB.05Mn4+O2
Quartz4.DA.05SiO2
var: Smoky Quartz4.DA.05SiO2
Rutile4.DB.05TiO2
Group 5 - Nitrates and Carbonates
'Aragonite' ?5.AB.15CaCO3
'Calcite'5.AB.05CaCO3
'Cerussite'5.AB.15PbCO3
'Hydrozincite'5.BA.15Zn5(CO3)2(OH)6
'Malachite' ?5.BA.10Cu2(CO3)(OH)2
Smithsonite ?5.AB.05ZnCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
'Anglesite' ?7.AD.35PbSO4
'Baryte'7.AD.35BaSO4
'Copiapite'7.DB.35Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
'Jarosite' ?7.BC.10KFe3+ 3(SO4)2(OH)6
'Melanterite'7.CB.35Fe2+(H2O)6SO4 · H2O
Wulfenite7.GA.05Pb(MoO4)
Group 8 - Phosphates, Arsenates and Vanadates
'Autunite' ?8.EB.05Ca(UO2)2(PO4)2 · 11H2O
'Fluorapatite'8.BN.05Ca5(PO4)3F
Pyromorphite8.BN.05Pb5(PO4)3Cl
Vanadinite ?8.BN.05Pb5(VO4)3Cl
Group 9 - Silicates
'Actinolite'9.DE.10☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
'Albite'9.FA.35Na(AlSi3O8)
var: Oligoclase9.FA.35(Na,Ca)[Al(Si,Al)Si2O8]
'Almandine'9.AD.25Fe2+3Al2(SiO4)3
'Annite'9.EC.20KFe2+3(AlSi3O10)(OH)2
'Axinite-(Fe)'9.BD.20Ca2Fe2+Al2BSi4O15OH
'Beryl' ?9.CJ.05Be3Al2(Si6O18)
'Clinozoisite'9.BG.05a{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
'Datolite' ?9.AJ.20CaB(SiO4)(OH)
'Diopside'9.DA.15CaMgSi2O6
'Epidote'9.BG.05a{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
'Grossular'9.AD.25Ca3Al2(SiO4)3
'Harmotome'9.GC.10(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
'Hemimorphite'9.BD.10Zn4Si2O7(OH)2 · H2O
'Kaolinite' ?9.ED.05Al2(Si2O5)(OH)4
'Kyanite'9.AF.15Al2(SiO4)O
'Laumontite'9.GB.10CaAl2Si4O12 · 4H2O
'Microcline'9.FA.30K(AlSi3O8)
'Montmorillonite' ?9.EC.40(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
'Mordenite' ?9.GD.35(Na2,Ca,K2)Al2Si10O24 · 7H2O
'Muscovite'9.EC.15KAl2(AlSi3O10)(OH)2
var: Sericite9.EC.15KAl2(AlSi3O10)(OH)2
'Natrolite' ?9.GA.05Na2Al2Si3O10 · 2H2O
Phlogopite ?9.EC.20KMg3(AlSi3O10)(OH)2
Prehnite ?9.DP.20Ca2Al2Si3O10(OH)2
Schorl9.CK.05Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3(OH)
Sillimanite9.AF.05Al2(SiO4)O
Staurolite9.AF.30Fe2+2Al9Si4O23(OH)
Stilbite-Ca9.GE.10NaCa4[Al9Si27O72] · nH2O
Stilpnomelane ?9.EG.40(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
Titanite9.AG.15CaTi(SiO4)O
Zircon9.AD.30Zr(SiO4)
Unclassified Minerals, Rocks, etc.
'Apophyllite'-
'Chabazite'-
'Chlorite Group'-
'Heulandite subgroup'-
'Hornblende'-
'Limonite'-(Fe,O,OH,H2O)
Phillipsite ?-
Stilbite subgroup-

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Semi-metals and non-metals
Graphite1.3.6.2C
Sulphur ?1.3.5.1S8
Group 2 - SULFIDES
AmXp, with m:p = 1:1
Galena2.8.1.1PbS
Greenockite ?2.8.7.2CdS
Pyrrhotite2.8.10.1Fe7S8
Sphalerite2.8.2.1ZnS
Wurtzite ?2.8.7.1(Zn,Fe)S
AmBnXp, with (m+n):p = 1:1
Chalcopyrite2.9.1.1CuFeS2
AmBnXp, with (m+n):p = 1:2
Pyrite2.12.1.1FeS2
Group 4 - SIMPLE OXIDES
A2X3
Ilmenite4.3.5.1Fe2+TiO3
AX2
Anatase4.4.4.1TiO2
Brookite4.4.5.1TiO2
Pyrolusite ?4.4.1.4Mn4+O2
Rutile4.4.1.1TiO2
Group 6 - HYDROXIDES AND OXIDES CONTAINING HYDROXYL
XO(OH)
Goethite6.1.1.2α-Fe3+O(OH)
Group 7 - MULTIPLE OXIDES
AB2X4
Magnetite7.2.2.3Fe2+Fe3+2O4
Group 9 - NORMAL HALIDES
AX2
Fluorite9.2.1.1CaF2
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
Cerussite14.1.3.4PbCO3
Smithsonite ?14.1.1.6ZnCO3
Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
Malachite ?16a.3.1.1Cu2(CO3)(OH)2
Hydrozincite16a.4.1.1Zn5(CO3)2(OH)6
Group 28 - ANHYDROUS ACID AND NORMAL SULFATES
AXO4
Anglesite ?28.3.1.3PbSO4
Baryte28.3.1.1BaSO4
Group 29 - HYDRATED ACID AND NORMAL SULFATES
AXO4·xH2O
Melanterite29.6.10.1Fe2+(H2O)6SO4 · H2O
Group 30 - ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
(AB)2(XO4)Zq
Jarosite ?30.2.5.1KFe3+ 3(SO4)2(OH)6
Group 31 - HYDRATED SULFATES CONTAINING HYDROXYL OR HALOGEN
Miscellaneous
Copiapite31.10.5.1Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
Group 40 - HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
AB2(XO4)2·xH2O, containing (UO2)2+
Autunite ?40.2a.1.1Ca(UO2)2(PO4)2 · 11H2O
Group 41 - ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
A5(XO4)3Zq
Fluorapatite41.8.1.1Ca5(PO4)3F
Pyromorphite41.8.4.1Pb5(PO4)3Cl
Vanadinite ?41.8.4.3Pb5(VO4)3Cl
Group 48 - ANHYDROUS MOLYBDATES AND TUNGSTATES
AXO4
Wulfenite48.1.3.1Pb(MoO4)
Group 51 - NESOSILICATES Insular SiO4 Groups Only
Insular SiO4 Groups Only with cations in [6] and >[6] coordination
Almandine51.4.3a.2Fe2+3Al2(SiO4)3
Grossular51.4.3b.2Ca3Al2(SiO4)3
Insular SiO4 Groups Only with cations in >[6] coordination
Zircon51.5.2.1Zr(SiO4)
Group 52 - NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
Insular SiO4 Groups and O, OH, F, and H2O with cations in [4] and >[4] coordination
Kyanite52.2.2c.1Al2(SiO4)O
Sillimanite52.2.2a.1Al2(SiO4)O
Staurolite52.2.3.1Fe2+2Al9Si4O23(OH)
Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] and/or >[6] coordination
Titanite52.4.3.1CaTi(SiO4)O
Group 54 - NESOSILICATES Borosilicates and Some Beryllosilicates
Borosilicates and Some Beryllosilicates with B in [4] coordination
Datolite ?54.2.1a.1CaB(SiO4)(OH)
Group 56 - SOROSILICATES Si2O7 Groups, With Additional O, OH, F and H2O
Si2O7 Groups and O, OH, F, and H2O with cations in [4] coordination
Hemimorphite56.1.2.1Zn4Si2O7(OH)2 · H2O
Si2O7 Groups and O, OH, F, and H2O with cations in [4] and/or >[4] coordination
Axinite-(Fe)56.2.2.1Ca2Fe2+Al2BSi4O15OH
Group 58 - SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
Clinozoisite58.2.1a.4{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
Epidote58.2.1a.7{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Group 61 - CYCLOSILICATES Six-Membered Rings
Six-Membered Rings with [Si6O18] rings; possible (OH) and Al substitution
Beryl ?61.1.1.1Be3Al2(Si6O18)
Six-Membered Rings with borate groups
Schorl61.3.1.10Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3(OH)
Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1)
Single-Width Unbranched Chains, W=1 with chains P=2
Diopside65.1.3a.1CaMgSi2O6
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Annite71.2.2b.3KFe2+3(AlSi3O10)(OH)2
Muscovite71.2.2a.1KAl2(AlSi3O10)(OH)2
Phlogopite ?71.2.2b.1KMg3(AlSi3O10)(OH)2
Sheets of 6-membered rings with 2:1 clays
Montmorillonite ?71.3.1a.2(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Group 72 - PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with 4-membered rings
Prehnite ?72.1.3.1Ca2Al2Si3O10(OH)2
Group 74 - PHYLLOSILICATES Modulated Layers
Modulated Layers with joined islands
Stilpnomelane ?74.1.1.1(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Si Tetrahedral Frameworks - SiO2 with H2O and organics
Opal75.2.1.1SiO2 · nH2O
Group 76 - TECTOSILICATES Al-Si Framework
Al-Si Framework with Al-Si frameworks
Albite76.1.3.1Na(AlSi3O8)
Microcline76.1.1.5K(AlSi3O8)
Group 77 - TECTOSILICATES Zeolites
Zeolite group - True zeolites
Harmotome77.1.3.5(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Laumontite77.1.1.4CaAl2Si4O12 · 4H2O
Mordenite ?77.1.6.1(Na2,Ca,K2)Al2Si10O24 · 7H2O
Natrolite ?77.1.5.1Na2Al2Si3O10 · 2H2O
Stilbite-Ca77.1.4.3NaCa4[Al9Si27O72] · nH2O
Unclassified Minerals, Rocks, etc.
Actinolite-☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Albite
var: Oligoclase
-(Na,Ca)[Al(Si,Al)Si2O8]
'Apophyllite'-
Aragonite ?-CaCO3
'Chabazite'-
'Chlorite Group'-
'Heulandite subgroup'-
'Hornblende'-
Kaolinite ?-Al2(Si2O5)(OH)4
'Limonite'-(Fe,O,OH,H2O)
Muscovite
var: Sericite
-KAl2(AlSi3O10)(OH)2
Opal
var: Opal-AN
-SiO2 · nH2O
'Phillipsite' ?-
Quartz
var: Smoky Quartz
-SiO2
'Stilbite subgroup'-

List of minerals for each chemical element

HHydrogen
H Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
H AnniteKFe32+(AlSi3O10)(OH)2
H AutuniteCa(UO2)2(PO4)2 · 11H2O
H Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
H Clinozoisite{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
H CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
H DatoliteCaB(SiO4)(OH)
H Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
H Goethiteα-Fe3+O(OH)
H Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
H HemimorphiteZn4Si2O7(OH)2 · H2O
H HydrozinciteZn5(CO3)2(OH)6
H JarositeKFe3+ 3(SO4)2(OH)6
H KaoliniteAl2(Si2O5)(OH)4
H LaumontiteCaAl2Si4O12 · 4H2O
H Limonite(Fe,O,OH,H2O)
H MalachiteCu2(CO3)(OH)2
H MelanteriteFe2+(H2O)6SO4 · H2O
H Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
H Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
H MuscoviteKAl2(AlSi3O10)(OH)2
H NatroliteNa2Al2Si3O10 · 2H2O
H OpalSiO2 · nH2O
H Opal (var: Opal-AN)SiO2 · nH2O
H PhlogopiteKMg3(AlSi3O10)(OH)2
H PrehniteCa2Al2Si3O10(OH)2
H SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
H Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
H StauroliteFe22+Al9Si4O23(OH)
H Stilbite-CaNaCa4[Al9Si27O72] · nH2O
H Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
BeBeryllium
Be BerylBe3Al2(Si6O18)
BBoron
B Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
B DatoliteCaB(SiO4)(OH)
B SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
CCarbon
C AragoniteCaCO3
C CalciteCaCO3
C CerussitePbCO3
C GraphiteC
C HydrozinciteZn5(CO3)2(OH)6
C MalachiteCu2(CO3)(OH)2
C SmithsoniteZnCO3
OOxygen
O Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
O AlbiteNa(AlSi3O8)
O AlmandineFe32+Al2(SiO4)3
O AnataseTiO2
O AnglesitePbSO4
O AnniteKFe32+(AlSi3O10)(OH)2
O AragoniteCaCO3
O AutuniteCa(UO2)2(PO4)2 · 11H2O
O Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
O BaryteBaSO4
O BerylBe3Al2(Si6O18)
O BrookiteTiO2
O CalciteCaCO3
O CerussitePbCO3
O Clinozoisite{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
O CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
O DatoliteCaB(SiO4)(OH)
O DiopsideCaMgSi2O6
O Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
O FluorapatiteCa5(PO4)3F
O Goethiteα-Fe3+O(OH)
O GrossularCa3Al2(SiO4)3
O Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
O HemimorphiteZn4Si2O7(OH)2 · H2O
O HydrozinciteZn5(CO3)2(OH)6
O IlmeniteFe2+TiO3
O JarositeKFe3+ 3(SO4)2(OH)6
O KaoliniteAl2(Si2O5)(OH)4
O KyaniteAl2(SiO4)O
O LaumontiteCaAl2Si4O12 · 4H2O
O Limonite(Fe,O,OH,H2O)
O MagnetiteFe2+Fe23+O4
O MalachiteCu2(CO3)(OH)2
O MelanteriteFe2+(H2O)6SO4 · H2O
O MicroclineK(AlSi3O8)
O Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
O Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
O MuscoviteKAl2(AlSi3O10)(OH)2
O NatroliteNa2Al2Si3O10 · 2H2O
O Albite (var: Oligoclase)(Na,Ca)[Al(Si,Al)Si2O8]
O OpalSiO2 · nH2O
O Opal (var: Opal-AN)SiO2 · nH2O
O PhlogopiteKMg3(AlSi3O10)(OH)2
O PrehniteCa2Al2Si3O10(OH)2
O PyrolusiteMn4+O2
O PyromorphitePb5(PO4)3Cl
O QuartzSiO2
O RutileTiO2
O SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
O Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
O SillimaniteAl2(SiO4)O
O SmithsoniteZnCO3
O Quartz (var: Smoky Quartz)SiO2
O StauroliteFe22+Al9Si4O23(OH)
O Stilbite-CaNaCa4[Al9Si27O72] · nH2O
O Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
O TitaniteCaTi(SiO4)O
O VanadinitePb5(VO4)3Cl
O WulfenitePb(MoO4)
O ZirconZr(SiO4)
FFluorine
F FluorapatiteCa5(PO4)3F
F FluoriteCaF2
NaSodium
Na AlbiteNa(AlSi3O8)
Na Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Na Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Na Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
Na NatroliteNa2Al2Si3O10 · 2H2O
Na Albite (var: Oligoclase)(Na,Ca)[Al(Si,Al)Si2O8]
Na SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
Na Stilbite-CaNaCa4[Al9Si27O72] · nH2O
Na Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
MgMagnesium
Mg Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Mg DiopsideCaMgSi2O6
Mg Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Mg PhlogopiteKMg3(AlSi3O10)(OH)2
Mg Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
AlAluminium
Al AlbiteNa(AlSi3O8)
Al AlmandineFe32+Al2(SiO4)3
Al AnniteKFe32+(AlSi3O10)(OH)2
Al Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
Al BerylBe3Al2(Si6O18)
Al Clinozoisite{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
Al Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Al GrossularCa3Al2(SiO4)3
Al Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Al KaoliniteAl2(Si2O5)(OH)4
Al KyaniteAl2(SiO4)O
Al LaumontiteCaAl2Si4O12 · 4H2O
Al MicroclineK(AlSi3O8)
Al Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Al Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al NatroliteNa2Al2Si3O10 · 2H2O
Al Albite (var: Oligoclase)(Na,Ca)[Al(Si,Al)Si2O8]
Al PhlogopiteKMg3(AlSi3O10)(OH)2
Al PrehniteCa2Al2Si3O10(OH)2
Al SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
Al Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Al SillimaniteAl2(SiO4)O
Al StauroliteFe22+Al9Si4O23(OH)
Al Stilbite-CaNaCa4[Al9Si27O72] · nH2O
Al Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
SiSilicon
Si Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Si AlbiteNa(AlSi3O8)
Si AlmandineFe32+Al2(SiO4)3
Si AnniteKFe32+(AlSi3O10)(OH)2
Si Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
Si BerylBe3Al2(Si6O18)
Si Clinozoisite{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
Si DatoliteCaB(SiO4)(OH)
Si DiopsideCaMgSi2O6
Si Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Si GrossularCa3Al2(SiO4)3
Si Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Si HemimorphiteZn4Si2O7(OH)2 · H2O
Si KaoliniteAl2(Si2O5)(OH)4
Si KyaniteAl2(SiO4)O
Si LaumontiteCaAl2Si4O12 · 4H2O
Si MicroclineK(AlSi3O8)
Si Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Si Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si NatroliteNa2Al2Si3O10 · 2H2O
Si Albite (var: Oligoclase)(Na,Ca)[Al(Si,Al)Si2O8]
Si OpalSiO2 · nH2O
Si Opal (var: Opal-AN)SiO2 · nH2O
Si PhlogopiteKMg3(AlSi3O10)(OH)2
Si PrehniteCa2Al2Si3O10(OH)2
Si QuartzSiO2
Si SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
Si Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Si SillimaniteAl2(SiO4)O
Si Quartz (var: Smoky Quartz)SiO2
Si StauroliteFe22+Al9Si4O23(OH)
Si Stilbite-CaNaCa4[Al9Si27O72] · nH2O
Si Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
Si TitaniteCaTi(SiO4)O
Si ZirconZr(SiO4)
PPhosphorus
P AutuniteCa(UO2)2(PO4)2 · 11H2O
P FluorapatiteCa5(PO4)3F
P PyromorphitePb5(PO4)3Cl
SSulfur
S AnglesitePbSO4
S BaryteBaSO4
S ChalcopyriteCuFeS2
S CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
S GalenaPbS
S GreenockiteCdS
S JarositeKFe3+ 3(SO4)2(OH)6
S MelanteriteFe2+(H2O)6SO4 · H2O
S PyriteFeS2
S PyrrhotiteFe7S8
S SphaleriteZnS
S SulphurS8
S Wurtzite(Zn,Fe)S
ClChlorine
Cl PyromorphitePb5(PO4)3Cl
Cl VanadinitePb5(VO4)3Cl
KPotassium
K AnniteKFe32+(AlSi3O10)(OH)2
K Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
K JarositeKFe3+ 3(SO4)2(OH)6
K MicroclineK(AlSi3O8)
K Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
K MuscoviteKAl2(AlSi3O10)(OH)2
K PhlogopiteKMg3(AlSi3O10)(OH)2
K Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
K Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
CaCalcium
Ca Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Ca AragoniteCaCO3
Ca AutuniteCa(UO2)2(PO4)2 · 11H2O
Ca Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
Ca CalciteCaCO3
Ca Clinozoisite{Ca2}{Al3}(Si2O7)(SiO4)O(OH)
Ca DatoliteCaB(SiO4)(OH)
Ca DiopsideCaMgSi2O6
Ca Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Ca FluorapatiteCa5(PO4)3F
Ca FluoriteCaF2
Ca GrossularCa3Al2(SiO4)3
Ca Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
Ca LaumontiteCaAl2Si4O12 · 4H2O
Ca Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Ca Mordenite(Na2,Ca,K2)Al2Si10O24 · 7H2O
Ca Albite (var: Oligoclase)(Na,Ca)[Al(Si,Al)Si2O8]
Ca PrehniteCa2Al2Si3O10(OH)2
Ca Stilbite-CaNaCa4[Al9Si27O72] · nH2O
Ca Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
Ca TitaniteCaTi(SiO4)O
TiTitanium
Ti AnataseTiO2
Ti BrookiteTiO2
Ti IlmeniteFe2+TiO3
Ti RutileTiO2
Ti TitaniteCaTi(SiO4)O
VVanadium
V VanadinitePb5(VO4)3Cl
MnManganese
Mn PyrolusiteMn4+O2
FeIron
Fe Actinolite☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Fe AlmandineFe32+Al2(SiO4)3
Fe AnniteKFe32+(AlSi3O10)(OH)2
Fe Axinite-(Fe)Ca2Fe2+Al2BSi4O15OH
Fe ChalcopyriteCuFeS2
Fe CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
Fe Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Fe Goethiteα-Fe3+O(OH)
Fe IlmeniteFe2+TiO3
Fe JarositeKFe3+ 3(SO4)2(OH)6
Fe Limonite(Fe,O,OH,H2O)
Fe MagnetiteFe2+Fe23+O4
Fe MelanteriteFe2+(H2O)6SO4 · H2O
Fe PyriteFeS2
Fe PyrrhotiteFe7S8
Fe SchorlNa(Fe32+)Al6(Si6O18)(BO3)3(OH)3(OH)
Fe StauroliteFe22+Al9Si4O23(OH)
Fe Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
CuCopper
Cu ChalcopyriteCuFeS2
Cu MalachiteCu2(CO3)(OH)2
ZnZinc
Zn HemimorphiteZn4Si2O7(OH)2 · H2O
Zn HydrozinciteZn5(CO3)2(OH)6
Zn SmithsoniteZnCO3
Zn SphaleriteZnS
Zn Wurtzite(Zn,Fe)S
ZrZirconium
Zr ZirconZr(SiO4)
MoMolybdenum
Mo WulfenitePb(MoO4)
CdCadmium
Cd GreenockiteCdS
BaBarium
Ba BaryteBaSO4
Ba Harmotome(Ba0.5,Ca0.5,K,Na)5[Al5Si11O32] · 12H2O
PbLead
Pb AnglesitePbSO4
Pb CerussitePbCO3
Pb GalenaPbS
Pb PyromorphitePb5(PO4)3Cl
Pb VanadinitePb5(VO4)3Cl
Pb WulfenitePb(MoO4)
UUranium
U AutuniteCa(UO2)2(PO4)2 · 11H2O

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Ordovician - Neoproterozoic
443.8 - 1000 Ma



ID: 3190671
Precambrian-Phanerozoic sedimentary rocks

Age: Neoproterozoic to Ordovician (443.8 - 1000 Ma)

Lithology: Mudstone-carbonate-sandstone-conglomerate

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Early Ordovician
470 - 485.4 Ma



ID: 3020282
Ratlum Mountain Schist

Age: Early Ordovician (470 - 485.4 Ma)

Stratigraphic Name: Ratlum Mountain Schist

Description: Gray, medium-grained, interlayered schist and granofels, composed of quartz, oligoclase, muscovite (in the schist), biotite, and garnet, also staurolite and kyanite in the schist. Numerous layers and lenses of amphibolite; also some of quartz-spessartine (coticule) and calc-silicate rock.

Comments: Part of Central Lowlands; Iapetus (Oceanic) Terrane - Connecticut Valley Synclinorium; Hartland Belt. Equivalents of Savoy Schist of Massachusetts (Emerson, 1898, 1917) (CT009, CT010) and of Moretown Formation of Vermont and Massachusetts (Bedrock Geologic Map of Massachusetts, Zen and others, 1983) (CT011) (includes Golden Hill and Ratlum Mountain Schists) (Lower? Ordovician).

Lithology: Major:{schist,granofels}, Minor:{amphibolite}, Incidental:{calc silicate rock}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Zodac, Peter. (1959), Minerals at Thomaston Dam, Connecticut; Rocks & Minerals: 34: 3.
Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Myer, George H. (1962), Hydrothermal Wurtzite at Thomaston Dam, Connecticut. American Mineralogist: 47(7-8): 977-979.
Hiller, John. (1968), Collecting at Thomaston, Conn. Rocks & Minerals: 43(10): 746-747.
Ryerson, Kathleen. (1972), Rock Hound's Guide to Connecticut. Pequot Press: 36-37.
Yedlin, Neal. (1973a), Yedlin on Micromounting. Mineralogical Record: 4(2).
Yedlin, Neal. (1973b), Yedlin on Micromounting. Mineralogical Record: 4(6).
Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Molon, Joseph. (1976), Minerals from Thomaston Dam, Thomaston, Connecticut; Rocks & Minerals: 51: 449.
Henderson, William A. (1979), Microminerals. Thomaston Dam. Mineralogical Record: 10: 239-241.
Shelton, Bill and Webster, Bud. (1979), Mineral Collector's Field Guide: The Northeast. Mineralogy, Wallingford, Connecticut: 46-49.
Segeler, Curt and Molon, Joseph. (1985), The Thomaston Dam Site, Thomaston, Connecticut; Rocks & Minerals: 60(3): 119-124.
Vogt, Wolfgang. (1991), Rediscovering Thomaston Dam. Lapidary Journal: April.
Januzzi, Ronald. E. (1994), Mineral Data Book - Western Connecticut and Environs. Mineralogical Press, Danbury, Connecticut.
Henderson, William A. (1995), Microminerals of Connecticut; Rocks & Minerals: 70(6): 420-425.
Weber, Marcelle H. and Earle C. Sullivan. (1995), Connecticut Mineral Locality Index. Rocks & Minerals (Connecticut Issue): 70(6): 399.


This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2018, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: November 19, 2018 20:04:50 Page generated: August 30, 2018 19:48:21
Go to top of page