Gold

Eagle's Nest Mine (Mystery Wind Mine), Placer Co., California, USA
© 2004 ROM

Show Gold Photos (1039)

Formula:

System:

Isometric

Colour:

Rich yellow, paling to ...

Lustre:

Metallic

Hardness:

2½ - 3

Name:

From Anglo-Saxon "gold", yellow; Latin "aurum".

Copper Group. Gold-Silver Series and Gold-Palladium Series.

A native element and precious metal, Gold has long been prized for its beauty, resistance to chemical attack and workability. As it is found as a native element, has a relatively low melting point (1063 degrees Celsius) and is malleable, it has been used by mankind for thousands of years.

Gold is used as a standard for international currency and is also widely used in jewelry, electronics (where its superb properties as a conductor help offset its tremendous cost), dentistry and in photographic processes.

Gold occurs in significant amounts in three main types of deposits: veins of hydrothermal and related origin; in consolidated placer deposits, and in unconsolidated placer deposits. It may also occur in granitic pegmatites, in contact metamorphic deposits, and in hypo-thermal deposits. It is commonly found as disseminated grains in Quartz veins with Pyrite and other sulphides, or as rounded grains, flakes or nuggets in placer deposits and in streams and rivers. Gold is often panned from such deposits by taking advantage of its high density to wash away the lighter sediments from a pan or sluice.
Nuggets are (almost) exclusively hypogene in origin (Hough et al., 2007).

Classification of Gold

IMA status:

Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"

Strunz 8th edition ID:

1/A.01-40

Nickel-Strunz 10th (pending) edition ID:

1.AA.05

1 : ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
A : Metals and Intermetallic Alloys
A : Copper-cupalite family

Dana 7th edition ID:

1.1.1.1

Dana 8th edition ID:

1.1.1.1

1 : NATIVE ELEMENTS AND ALLOYS
1 : Metals, other than the Platinum Group

Hey's CIM Ref.:

1.5

1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)

mindat.org URL:

http://www.mindat.org/min-1720.html
Please feel free to link to this page.

Occurrences of Gold

Geological Setting:

1) Primary hydrothermal veins
2) Volcanic
3) Alluvial

Physical Properties of Gold

Lustre:

Metallic

Diaphaneity (Transparency):

Opaque

Colour:

Rich yellow, paling to whitish-yellow with increasing silver; blue & green in transmitted light (only thinnest folia [gold leaf])

Streak:

Shining yellow

Hardness (Mohs):

2½ - 3

Hardness (Vickers):

VHN₁₀=30 - 34 kg/mm²

Hardness Data:

Measured

Tenacity:

Malleable

Cleavage:

None Observed
None

Fracture:

Hackly

Density (measured):

15 - 19.3 g/cm³

Density (calculated):

19.309 g/cm³

Comment:

Calculated density at 0° C.

Crystallography of Gold

Crystal System:

Isometric

Class (H-M):

m3m (4/m 3 2/m) - Hexoctahedral

Space Group:

Fm3m {F4/m 3 2/m}

Cell Parameters:

a = 4.0786Å

Unit Cell Volume:

V 67.85 Å³ (Calculated from Unit Cell)

Morphology:

Usually crude to rounded octahedra, cubes and dodecahedra to 2 cm. Often elongated along [100] or [111] directions, forming herring bone and dendritic twins. Flattened {111} plates with triangular octahedral faces. Rarely as wires ([111] elongation); reticulated; dendritic; arborescent; filiform; spongy; also massive in rounded fragments, flattened grains and scales (gold dust).

Twinning:

Common on (111) to give herring bone twins. Repeated on (111) to give stacks of spinel twins that form hexagonal wires.

Crystal Atlas:

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Gold no.1 - Goldschmidt (1913-1926)

Gold no.3 - Goldschmidt (1913-1926)

Gold no.4 - Goldschmidt (1913-1926)

Gold no.17 - Goldschmidt (1913-1926)

Gold no.46 - Goldschmidt (1913-1926)

Gold no.47 - Goldschmidt (1913-1926)

About Crystal Atlas

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The mindat.org Crystal Atlas allows you to view a selection of crystal drawings of real and idealised crystal forms for this mineral and, in certain cases, 3d rotating crystal objects. You need Java to see these. You can download Java for free - click here to download Java

The 3d models and java code are kindly provided by www.smorf.nl. You can control the movement of the models by holding down the left mouse-button over the 3d model and moving your mouse. Keyboard controls are:

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Structure

Reference
Wyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Cubic closest packed, ccp, structure. Crystal Structures 1:7-83.

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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:

d-spacing		Intensity
2.355		(100)
2.039		(52)
1.230		(36)
1.442		(32)
0.9357		(23)
0.8325		(23)

Optical Data of Gold

Type:

Isotropic

Type:

Isotropic

Reflectivity:

400nm	R=24.9%
420nm	R=26.5%
440nm	R=28.1%
460nm	R=31.6%
480nm	R=39.0%
500nm	R=49.5%
520nm	R=57.8%
540nm	R=63.4%
580nm	R=67.8%
600nm	R=71.0%
620nm	R=73.8%
640nm	R=76.1%
660nm	R=78.2%
680nm	R=81.9%
700nm	R=83.6%

Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 83.6%.

Colour in reflected light:

Yellow to white with increasing silver, reddish with copper

Internal Reflections:

none

Pleochroism:

Non-pleochroic

Chemical Properties of Gold

Formula:

Essential elements:

All elements listed in formula:

CAS Registry number:

7440-57-5

CAS Registry numbers are published by the American Chemical Society

Analytical Data:

Gold forms series with silver(electrum 30-45 % Ag, küstelite < 80% Ag) and palladium (porpezite 5-10% Pd). The series with copper is broken by the intermetallic compounds auricupride and tetra-auricupride.

      1      2      3      4     5 
Au   99.91  85.21  90.99  94.22 73.54
Ag    0.09  14.71   3.53   2.84 20.92
Cu                  5.32   0.11  4.27
Fe                  0.07             
Bi                         2.82      
Sn                               0.28
Pb                               0.20
Zn                               0.77
Total 100   99.92  99.91 100.09 99.98
density     16.90 17.587  18.22

1)Sponge gold, 
2)Ostrig Bugoz, Don Valley, Russia,
3)Borneo,
4)Schillotssetsky Mine, Zavod, Russia,
5)Electrum, West Africa

Empirical Formula:

Common Impurities:

Ag,Cu,Pd

Relationship of Gold to other Species

Series:

Forms a series with Silver (see here)
Forms a series with Palladium (see here)

Member of Group:

Common Associates:

1.AA.05

1.AA.05

1.AA.05

(Au, Ag)

1.AA.05

1.AA.05

1.AA.05

1.AA.05

(Cu,Pd,Au)

1.AA.05

UM1991-06-E:AuCu

1.AA.10a

Auricupride

1.AA.10b

Tetra-auricupride

AuCu

1.AA.10a

Cuproauride

1.AA.15

Anyuiite

Au(Pb,Sb)

1.AA.15

Khatyrkite

(Cu,Zn)Al

1.AA.15

Iodine

1.AA.15

Novodneprite

AuPb

1.AA.15

UM1985-02-E:AlZn

ZnAl

1.AA.20

Cupalite

(Cu,Zn)Al

1.AA.25

1.1

1.2

1.6

1.7

AuCu

1.8

Zinc

1.9

Cadmium

1.10

Danbaite

CuZn

1.11

Zhanghengite

CuZn

1.12

1.13

1.14

1.15

1.16

1.1

0.9

1.17

Paraschachnerite

1.18

Luanheite

1.19

Weishanite

(Au,Ag)

1.20

Indium

1.21

Aluminium

1.22

Khatyrkite

(Cu,Zn)Al

1.23

Cupalite

(Cu,Zn)Al

1.24

1.25

1.26

1.27

1.28

1.29

1.30

1.31

Au(Pb,Sb)

1.31

Novodneprite

AuPb

1.32

Leadamalgam

HgPb

1.33

Arsenic

1.34

Arsenolamprite

1.35

Paxite

CuAs

1.36

Koutekite

1.37

Domeykite

1.38

Algodonite

(Cu

1-x

)

1.39

Novakite

AgAs

1.40

Kutinaite

AgAs

1.41

Antimony

1.42

Stibarsen

AsSb

1.43

Paradocrasite

1.44

Horsfordite

1.45

Cuprostibite

(Sb,Tl)

1.46

Allargentum

(Ag

1-x

)

1.47

Aurostibite

AuSb

1.48

1.49

1.50

1.51

1.52

1.53

1.54

1.55

1.56

1.57

1.58

1-x

(x=0.6)

1.59

Ferchromide

1.5

0.5-x

1.60

Wairauite

CoFe

1.61

Nickel

1.62

Kamacite

(Fe,Ni)

1.63

Taenite

(Fe,Ni)

1.64

Tetrataenite

FeNi

1.65

Awaruite

1.66

Palladium

(Pd,Pt)

1.67

Potarite

PdHg

1.68

Paolovite

1.69

Stannopalladinite

(Pd,Cu)

1.70

Cabriite

SnCu

1.71

Taimyrite

(Pd,Cu,Pt)

1.72

Atokite

(Pd,Pt)

1.73

Rustenburgite

(Pt,Pd)

1.74

Zvyagintsevite

(Pd,Pt,Au)

(Pb,Sn)

1.75

Plumbopalladinite

1.76

Osmium

(Os,Ir,Ru)

1.77

Iridium

(Ir,Os,Ru)

1.82

Platinum

1.83

Hongshiite

PtCu

1.84

Niggliite

PtSn

1.85

Isoferroplatinum

1.86

Tetraferroplatinum

PtFe

1.87

Tulameenite

CuFe

1.88

Ferronickelplatinum

FeNi

1.89

Rhodium

(Rh,Pt)

Related Minerals - Dana Grouping):

- +

1.1.1.2

Silver

1.1.1.3

Copper

Other Names for Gold

Synonyms:

Native Gold

Qori

Sol

Other Languages:

Afrikaans:	Goud
Albanian:	Ari
Amharic:	ወርቅ
Arabic:	ذهب
Armenian:	Ոսկի
Asturian:	Oru
Aymara:	Quri
Azeri:	Qızıl
Basque:	Urre
Belarusian:	Золата
Bengali:	সোনা
Bishnupriya Manipuri:	ঔরো
Bosnian (Latin Script):	Zlato
Bulgarian:	Злато
Catalan:	Or
Cherokee:	ᎠᏕᎸ ᏓᎶᏂᎨ
Chuvash:	Ылтăн
Corsican:	Oru
Croatian:	Zlato
Czech:	Zlato
Danish:	Guld
Dutch:	Goud
Erzya:	Сырне
Esperanto:	Oro
Estonian:	Kuld
Finnish:	Kulta
French:	Or Or natif
Friulian:	Aur
Galician:	Ouro
Gan:	金
Georgian:	ოქრო
German:	Gediegen Gold
Greek:	Χρυσός
Guarani:	Kuarepotiju
Gujarati:	સોનું
Haitian:	Lò
Hakka:	Kîm
Hebrew:	זהב
Hindi:	सोना
Hungarian:	Arany
Icelandic:	Gull
Ido:	Oro
Indonesian:	Emas
Irish Gaelic:	Ór
Italian:	Oro Oro nativo
Japanese:	金自然金
Javanese:	Emas
Kannada:	ಚಿನ್ನ
Kapampangan:	Gintu
Kazakh (Cyrillic Script):	Алтын
Kongo:	Wolo
Korean:	금
Kurdish (Latin Script):	Zêr
Latin:	Aurum
Latvian:	Zelts
Limburgian:	Goud
Lingala:	Wólo

Lithuanian:	Auksas
Lojban:	solji
Low Saxon:	Gold
Luxembourgish:	Gold
Macedonian:	Злато
Malay:	Emas
Malayalam:	സ്വര്‍ണ്ണം
Manx:	Airh
Marathi:	सोने
Min Nan:	Au
Mongolian (Cyrillic Script):	Алт
Nahuatl:	Cōztic teōcuitlatl
Norman:	Or
Norwegian (Bokmål):	Gull
Norwegian (Nynorsk):	Gull
Novial:	Ore
Occitan:	Aur
Persian:	طلا
Polish:	Złoto
Portuguese:	Ouro
Quechua:	Quri
Ripuarian:	Jold
Romanian:	Aur
Russian:	Золото
Sanskrit:	सुवर्णम्
Scottish Gaelic:	Òr
Serbian (Cyrillic Script):	Злато
Serbo-Croatian:	Zlato
Sicilian:	Oru
Simplified Chinese:	金
Slovak:	Zlato
Slovenian:	Zlato
Spanish:	Oro Oro nativo
Swahili:	Dhahabu
Swedish:	Guld Gediget Guld
Tagalog:	Ginto
Tajik (Cyrillic Script):	Зар
Tamil:	தங்கம்
Telugu:	బంగారం
Thai:	ทองคำ
Traditional Chinese:	金
Turkish:	Altın
Ukrainian:	Золото
Urdu:	سونا
Uzbek (Latin Script):	Oltin
Venetian:	Oro
Vietnamese:	Vàng
Welsh:	Aur
Yiddish:	גאלד
Zazaki:	Zern
Zhuang:	Gim
Zulu:	Igolide

Varieties:

Argentian Mercurian Gold	Argentocuproaurite	Argentocuproaurite-I	Argentocuproaurite-II	Bismuthian Gold
Cuprian Gold	Electrum	Mercurian Gold	Palladian Gold	Porpezite
Rhodite

Other Information

Fluorescence in UV light:

none

Thermal Behaviour:

Melting Point: 1062.4° ± 0.8°

Other Information:

Completely soluble with Copper. Insoluble in acids except aqua regia, with incomplete separation if more than 20% of silver is present.

Reported as spongy alteration pseudomorphs after Calaverite (Cripple Creek).

Health Warning:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

External Links

Search for toxicity information at the United States National Library of Medicine

Industrial Uses:

Electrical conductor, transparent reflective coating, jewelry, dentistry, coinage, decorative coatings

References for Gold

Reference List:

Wibel (1852) Naturwissenschaftlicher Verein, Hamburg . Abhandlungen und Verhandlungen: 2: 87.

Hatch, F.H. and J.A. Chalmers (1895) The Gold Mines of the Rand. London: Macmillan & Co.

Scupham, J.R. (1898) The Buried Rivers of California as a Source of Gold.
Mines and Minerals - Nov., 1898.

Outerbridge Jr., Alexander E. (1899) Marvellous Increase in Production of Gold
AP Popular Science Monthly, March, 1899.

Stone, George H. (1900) Gold Placers in Glaciated Regions. Mines and Minerals (June, 1900).

Krusch (1903) Zeitschrift für praktische Geologie, Berlin, hale a.S.: 11: 331 (Simpson analysis).

Spencer, Arthur C. (1904) The Geology of the Treadwell Ore Deposits, Douglas Island, Alaska. Transaction of the American Institute of Mining Engineers - Oct., 1904.

Douglass, Earl (1905) Source of the Placer Gold in Alder Gulch, Montana.
Mines and Minerals - Feb, 1905.

Evans, Horace F. (1905) The Source of the Fraser River Gold. Mining World - Sept. 2, 1905.

Wilkinson, H.L. (1905) Deep Placer Deposits of Victoria. Engineering and Mining Journal - Dec. 30, 1905.

Hart, T.S. (1906) Victorian Auriferous Occurrences. Australian Mining Standard - July 25, Aug. 1, 1906. Serial. 2 parts.

Nenadkevwitsch (1907) Academy of Sciences, St. Petersburg, Trav. Mus. géol.: 1: 81.

Gregory, John W. (1907) Gold Mining and Gold Production (Cantor Lecture). Journal of the Society of Arts - Sept. 13, 1907. Serial. lst part.

Tyrrell, J.B. (1907) Concentration of Gold in the Klondike. Economic Geology - June, 1907.

Garrison, F. Lynwood (1909) Nature of Mining and Scientific Press - May 29, 1909.

Samojloff (1909) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 46: 286.

Cochrane, N.D. (1910) Geological Features of Fiji. Australian Mining Standard - Aug. 3, 1910.

Day & Sosman (1910), American Journal of Science: 29: 93.

Lincoln, Francis C. (1911) Types of Canadian Gold Deposits. Economic Geology: 6: 247.

Thomas, Jr., Charles S. (1911) The Bugbear of Gold. Mining and Scientific Press - May 13, 1911.

Chernik (1912) Imperial Academy of Sciences, St. Petersburg, Trav. Mus. géol.: 6: 78.

Lakes, Arthur (1912) Geology of the Breckenridge Placers. Mines and Minerals - Feb, 1912.

Nenadkevwitsch (1914) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 53: 609.

Ungemach (1916) Bulletin de la Société française de Minéralogie: 39: 5.

Goldschmidt, V. (1918) Atlas der Krystallformen. 9 volumes, atlas, and text: Volume 4: 75.

Doelter, C. (1922) Handbuch der Mineral-chemie (in 4 volumes divided into parts): 3 [2]: 187.

McKeehan (1922) Physical Review, a Journal of Experimental and Theoretical Physics: 20: 424.

Uglow, W.L. and Johnston, W.A. (1923)Origin of the Placer Gold of the Barkerville Area, Cariboo District, British Columbia, Canada. Economic Geology, vol. 18(8), Sept. 1923: 541-561.

Holgersson and Sedström (1924) Annalen der Physik, Halle, Leipzig: 75: 143.

Weiss (1925) Proceedings of the Royal Society of London: 108: 643 (artificial Au-Ag alloys).

Strukturber. (1913-1926): 504 (Au-Cu series).

Ballard, S.M. (1928) Geology and Ore Deposits of the Rocky Bar Quadrangle. Idaho Bureau of Mines and Geology - Pamphlet, no. 26, 41 pp.

Ferraz, L.C. (1929) Compendio dos Mineraes do Brazil en forma Diccionario 645pp., Rio de Janeiro: 326.

Freise, F.W. (1931) Transportation of Gold by Organic Underground Solutions.
Economic Geology: 26(4) (June-July): 421-431.

Kellogg, A.E. (1931) Origin of Flour Gold in Black Sands. Mining Journal, Phoenix, Arizona: 14(20)(March 15th): 3-4 and 49-50.

Schneiderhöhn, Hans and Ramdohr, P. (1931) Lehrbuch der Erzmikroskopie. 2 volumes: vol. 2, 714 pp.: 64.

Strukturber. (1928-1932): 615 (Au-Cu series).

Drier and Walker (1933) Philosophical Magazine and Journal of Science: 16: 294.

Holloway, H.L. (1933) Alluvial Gold. Mining Magazine: 49(2) (Aug): 82-85.

Lindgren, W. (1933) Mineral Deposits. ); fourth edition, 930pp. New York.

Owen and Yates (1933), Philosophical Magazine and Journal of Science: 15: 472 (On spectroscopically pure gold).

Treskinsky, S. (1933) Desert Placers. Mining Magazine: 49(4) (Oct 1933): 219-223 [Description of type of placer deposit occurring in Persia].

Vegard and Kloster (1934) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 89: 560.

Bürg, G. (1935) Die sekundaeren Umlagerungen und Anreicherungen des des Goldes in den Goldseifen. Zeitschrift für Praktische Geologie: 43(9) (Sept 1935): 134-139.

Fisher, M.S. (1935) Origins and Composition of Alluvial Gold, With Special Reference to Morobe Goldfield, New Guinea. Institution of Mining and Metallurgy - Bulletin 365, 366, 367, 369 and 370 Feb 1935, 46 p supp plates, (discussion) Mar p. 1-27 Apr p. 23-4, June p. 31-2 and (author's reply) July p. 5-14.

Heyerhoff, H.A. (1935) Do Gold Nuggets Grow or Are They Born that Way? Mining and Metallurgy: 16(no. 340, Apr 1935): 195.

Jurriaanse (1935) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 90: 322 (Bi solubility in Au).

Fisher, M.S. (1936) Origin and Composition of Alluvial Gold, with Special Reference to Morobe Goldfield, New Guinea. Institution of Mining and Metallurgy - Bulletin 378, Mar 1936 p. 27-31.

Crampton, F.A. (1937) Occurrence of Gold in Stream Placers. Mining Journal (Phoenix, Arizona): 20(16): 3-4 and 33-34.

Emmons, W.H. (1937) Gold Deposits of the World. New York: McGraw Hill.

Van AUBEL, R. (1937) Sur l'origine de l'or et des pepites alluvionnaires.
Chronique des Mines Coloniales: 6(64): 238-262.

Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition, Volume I: 89-95.

Hoffman, A. (1947) Free Gold, Story of Canadian Mining Rinehart and Co. New York and Toronto, 420 p.

Gorbunov, E.Z. (1959) K voprosu o dal'nosti perenosa rossypnogo zolota ot korennykh istochnikov. Sovetskaya Geologiya: 2(6) (June 1959): 98-105. Transportation of gold during formation of placers].

Gorbunov, E.Z. (1963) Osobennosti razvitiya gidroseti i voprosy rossypnoi zolotonostnosti na Severo-Vostoke SSSR. Sovetskaya Geologiya n 4 Apr 1963 p 73-84 [Evolution features of hydrographic networks and problems of occurrence of gold, tin, and tungsten placers in northeast of the former Soviet Union].

Ivensen, Yu.P., Stepanov, A.A., and Chaikovskii, V.K. (1963) K probleme zolotonosnykh konglomeratov. Razvedka i Okhrana Nedr n 2 Feb 1963 p. 1-7
[Problem of gold-bearing conglomerates].

Sher, S.D. (1965) O sootnoshenii masshtabov korennoi i rossypnoi zolotonosnosti v razlichnykh zolotonosnykh provintsiyakh zemnogo shara. Sovetskaya Geologiya n 3 Mar 1965 p. 3-9 [Relationship between magnitude of primary gold deposits and gold placers in various gold-bearing provinces of world].

Hammett, A.B.J. (1966) The History of Gold. Kerrville: Braswell Printing.

Ferguson, S.A. et al (1973) Gold Deposits of Ontario (2 volumes); Ontario Division of Mines Circular 13.

Boyle (1979), The geochemistry of gold and its deposits.

Bache (1982): Les gisements d'or dans le monde.

Fleet, M.E. and Mumin, A.H. (1997): Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin trend gold deposits and laboratory synthesis. American Mineralogist: 82: 182-193.

Deksissa, D.J. and Koeberl, C. (2002) Geochemistry and petrography of gold-quartz-tourmaline veins of the Okote area, southern Ethiopia: implications for gold exploration. Mineralogy and Petrology: 75: 101-122.

Extra Lapis (English), No. 5 - Gold (2003).

Reich, M. Kesler, S.E., Utsunomiya, S., Palenik, C.S., Chryssoulis, S., and Ewing, R.C. (2005): Solubility of gold in arsenian pyrite. Geochimica et Cosmochimica Acta: 69: 2781-2796.

Frank Reith, Stephen L. Rogers, D. C. McPhail, Daryl Webb (2006): Biomineralization of Gold: Biofilms on Bacterioform Gold. Science 313, no. 5784, 233-236.

Hough, R. M., Butt, C. R. M., Reddy, S. M. & Verrall, M. (2007): Gold nuggets: supergene or hypogene? Australian Journal of Earth Sciences 54, 959-964.

Hough, R. M. et al. (2008): Naturally occurring gold nanoparticles and nanoplates. Geology 36, 571-574.

Hough, R. M., Butt, C. R. M. & Fischer-Bühner, J. (2009): The crystallography, metallography and composition of gold. Elements 5, 297-302.