Gachingite
A valid IMA mineral species
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Formula:
Au(Te1-xSex)
0.2 ≈ x ≤ 0.5
Specific Gravity:
10.47 (Calculated)
Crystal System:
Orthorhombic
Name:
Named for the Gaching ore occurrence of the Maletoyvayam epithermal deposit, Kamchatka, Russia, the type locality.
Known synthetic analogue. Chemically somewhat similar to maletoyvayamite and 'Unnamed (Au-Telluride-Selenide)'.
One of the very few minerals (as of 2021) with e-type slide plane in the structure.
One of the very few minerals (as of 2021) with e-type slide plane in the structure.
Unique Identifiers
Mindat ID:
55532
Long-form identifier:
mindat:1:1:55532:0
IMA Classification of Gachingite
Classification of Gachingite
2.CB.
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
C : Metal Sulfides, M: S = 1: 1 (and similar)
B : With Zn, Fe, Cu, Ag, etc.
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
C : Metal Sulfides, M: S = 1: 1 (and similar)
B : With Zn, Fe, Cu, Ag, etc.
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Gac | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Gachingite
Density:
10.47 g/cm3 (Calculated)
Optical Data of Gachingite
Anisotropism:
Strong, blue to dark blue to brown
Bireflectance:
Bluish-grey to deep grey
Reflectivity:
| Wavelength | R1 (%) | R2 (%) |
|---|---|---|
| 470nm | 39.9% | 40.3% |
| 546nm | 41.6% | 43.3% |
| 589nm | 42.0% | 43.7% |
| 650nm | 43.0% | 44.0% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 44.0%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Grey with a bluish tint
Chemistry of Gachingite
Mindat Formula:
Au(Te1-xSex)
0.2 ≈ x ≤ 0.5
0.2 ≈ x ≤ 0.5
Elements listed:
Crystallography of Gachingite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 7.5379 Å, b = 5.7415 Å, c = 8.8985 Å
Ratio:
a:b:c = 1.313 : 1 : 1.55
Unit Cell V:
385.12 ų
Z:
8
Comment:
Space group is Cmce
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.462 Å | (41) |
| 3.194 Å | (27) |
| 2.884 Å | (74) |
| 2.878 Å | (69) |
| 2.734 Å | (100) |
| 2.231 Å | (28) |
| 2.215 Å | (43) |
| 1.813 Å | (62) |
Type Occurrence of Gachingite
General Appearance of Type Material:
Individual droplet-like grains of sizes from 2 to 10 μm included in native gold.
Place of Conservation of Type Material:
mineralogical collections of the Central Siberian Geological Museum (CSGM), V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Science, prosp. Akad. Koptyuga 3, 630090 Novosibirsk, Russia, catalogue number V-10/1
Associated Minerals at Type Locality:
Other Language Names for Gachingite
Dutch:Gachingiet
German:Gachingit
Related Minerals - Strunz-mindat Grouping
| 2.CB. | Richardsite | Zn2CuGaS4 |
| 2.CB. | Okruginite | Cu2SnSe3 |
| 2.CB. | Hanswilkeite | KFeS2 |
| 2.CB. | Auroselenide | AuSe |
| 2.CB. | Ruizhongite | (Ag2◻)Pb3Ge2S8 |
| 2.CB. | Agmantinite | Ag2MnSnS4 |
| 2.CB. | Tolstykhite | Au3S4Te6 |
| 2.CB.05a | Hawleyite | CdS |
| 2.CB.05 | 'UM1998-15-S:CuFeZn' | Cu2Fe3Zn5S10 |
| 2.CB.05a | Coloradoite | HgTe |
| 2.CB.05a | Metacinnabar | HgS |
| 2.CB.05a | Tiemannite | HgSe |
| 2.CB.05a | Sphalerite | ZnS |
| 2.CB.05b | Sakuraiite | (Cu,Zn,Fe)3(In,Sn)S4 |
| 2.CB.05c | Polhemusite | (Zn,Hg)S |
| 2.CB.05a | Rudashevskyite | (Fe,Zn)S |
| 2.CB.05a | Stilleite | ZnSe |
| 2.CB.05a | Ishiharaite | (Cu,Ga,Fe,In,Zn)S |
| 2.CB.07a | 'Unnamed (Cu-Mn-Sn Sulphide)' | Cu2MnSnS4 |
| 2.CB.07a | Shenzhuangite | NiFeS2 |
| 2.CB.10b | Talnakhite | Cu9(Fe,Ni)8S16 |
| 2.CB.10b | Haycockite | Cu4Fe5S8 |
| 2.CB.10a | Lenaite | AgFeS2 |
| 2.CB.10a | Gallite | CuGaS2 |
| 2.CB.10a | Roquesite | CuInS2 |
| 2.CB.10a | Eskebornite | CuFeSe2 |
| 2.CB.10a | 'UM1984-30-S:CuFeSn' | Cu2Fe2Sn3S7 |
| 2.CB.10c | Omariniite | Cu8Fe2ZnGe2S12 |
| 2.CB.10a | Chalcopyrite | CuFeS2 |
| 2.CB.10a | 'Unnamed (Cu-Zn-In Sulphide)' | CuZn2InS4 |
| 2.CB.10b | Mooihoekite | Cu9Fe9S16 |
| 2.CB.10a | Laforêtite | AgInS2 |
| 2.CB.10b | Putoranite | Cu1.1Fe1.2S2 |
| 2.CB.15a | Velikite | Cu2HgSnS4 |
| 2.CB.15c | 'UM2006-11-S:CuFeGeZn' | Cu8(Fe,Zn)3Ge2S12 (?) |
| 2.CB.15a | Hocartite | Ag2(Fe2+,Zn)SnS4 |
| 2.CB.15a | Kësterite | Cu2ZnSnS4 |
| 2.CB.15a | Pirquitasite | Ag2ZnSnS4 |
| 2.CB.15a | Stannite | Cu2FeSnS4 |
| 2.CB.15c | Stannoidite | Cu+6Cu2+2(Fe2+,Zn)3Sn2S12 |
| 2.CB.15b | Mohite | Cu2SnS3 |
| 2.CB.15a | Černýite | Cu2CdSnS4 |
| 2.CB.15a | Idaite | Cu5FeS6 |
| 2.CB.15a | Ferrokësterite | Cu2FeSnS4 |
| 2.CB.15a | Kuramite | Cu3SnS4 |
| 2.CB.17a v | 'Arsenic-bearing Renierite' | Cu11GeAsFe4S16 |
| 2.CB.20 | Mawsonite | Cu6Fe2SnS8 |
| 2.CB.20 | Chatkalite | Cu6FeSn2S8 |
| 2.CB.30 | 'Frieseite' | Ag2Fe5S8 (?) |
| 2.CB.30 | Nekrasovite | Cu26V2(Sn,As,Sb)6S32 |
| 2.CB.30 | 'Argyropyrite' | near Ag2Fe7S11 |
| 2.CB.30 | Maikainite | Cu20(Fe,Cu)6Mo2Ge6S32 |
| 2.CB.30 | Colusite | Cu13VAs3S16 |
| 2.CB.30 | Germanite | Cu13Fe2Ge2S16 |
| 2.CB.30 | Germanocolusite | Cu26V2(Ge,As)6S32 |
| 2.CB.30 | Stibiocolusite | Cu13V(Sb,Sn,As)3S16 |
| 2.CB.30 | Ovamboite | Cu20(Fe,Cu,Zn)6W2Ge6S32 |
| 2.CB.35a | Morozeviczite | (Pb,Fe)3Ge1-xS4 |
| 2.CB.35a | Renierite | (Cu+,Zn)11Fe4(Ge4+,As5+)2S16 |
| 2.CB.35a | Hemusite | Cu6SnMoS8 |
| 2.CB.35b | Catamarcaite | Cu6GeWS8 |
| 2.CB.35a | Vinciennite | Cu+7Cu2+3Fe2+2Fe3+2Sn(As,Sb)S16 |
| 2.CB.35a | Kiddcreekite | Cu6SnWS8 |
| 2.CB.35a | Polkovicite | (Fe,Pb)3(Ge,Fe)1-xS4 |
| 2.CB.40 | Lautite | CuAsS |
| 2.CB.42 | Lingbaoite | AgTe3 |
| 2.CB.45 | Cadmoselite | CdSe |
| 2.CB.45 | Rambergite | MnS |
| 2.CB.45 | Buseckite | (Fe,Zn,Mn)S |
| 2.CB.45 | Maletoyvayamite | Au3Se4Te6 |
| 2.CB.45 | Greenockite | CdS |
| 2.CB.45 | Wurtzite | (Zn,Fe)S |
| 2.CB.47 | Murchisite | Cr5S6 |
| 2.CB.50 | 'Zincselenide' | ZnSe |
| 2.CB.50 | Wassonite | TiS |
| 2.CB.52 | 'Dzhezkazganite' | ReMoCu2PbS6 ? |
| 2.CB.55b | Isocubanite | CuFe2S3 |
| 2.CB.55a | Cubanite | CuFe2S3 |
| 2.CB.60 | Raguinite | TlFeS2 |
| 2.CB.60 | Picotpaulite | TlFe2S3 |
| 2.CB.65 | Argentopyrite | AgFe2S3 |
| 2.CB.65 | Sternbergite | AgFe2S3 |
| 2.CB.70 | Sulvanite | Cu3VS4 |
| 2.CB.75 | Vulcanite | CuTe |
| 2.CB.80 | Empressite | AgTe |
| 2.CB.85 | Muthmannite | AuAgTe2 |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Gachingite
mindat.org URL:
https://www.mindat.org/min-55532.html
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References for Gachingite
Localities for Gachingite
Showing 5 localities.
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Russia | |
| Shapovalova et al. (2025) |
| Miyawaki et al. (2021) +2 other references |
| Стрельников; МВ; Ханин; ДА; Япаскурт; ВО; Бритвин; СН; Плетнёв; ПА; et al. (n.d.) | |
| Strelnikov M. V. et al. (2025) | |
| Pekov et al. (2026) |
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