Grechishchevite
A valid IMA mineral species
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About Grechishchevite
Formula:
Hg2+3S2(Br,Cl,I)2
Colour:
Bright or dark orange, slowly darkening to brown-orange, then black.
Lustre:
Adamantine, Vitreous
Hardness:
2½
Specific Gravity:
7.23
Crystal System:
Tetragonal
Name:
Named by V.I. Vasil’ev, L.V. Usova, and N.A. Pal’chik in 1989 in honor of Oleg Konstantinovich Grechishchev (Олег Константинович Гречищев) (1936 – 2014), Institute of Geology, Novosibirsk, Russia, who did significant work on the Tuva mercury deposits.
This page provides mineralogical data about Grechishchevite.
Unique Identifiers
Mindat ID:
1744
Long-form identifier:
mindat:1:1:1744:8
GUID
(UUID V4):
(UUID V4):
db434989-d61e-4132-8a82-1d90aa6d9546
IMA Classification of Grechishchevite
Approved
IMA Formula:
Hg3S2BrCl0.5I0.5
First published:
1989
Classification of Grechishchevite
2.FC.15c
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
C : With Cl, Br, I (halide-sulfides)
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
C : With Cl, Br, I (halide-sulfides)
10.3.5.1
10 : OXYHALIDES AND HYDROXYHALIDES
3 : A3(O,OH)2Xq
10 : OXYHALIDES AND HYDROXYHALIDES
3 : A3(O,OH)2Xq
6.5.4
6 : Sulphosalts - Sulphostannates, Sulphogermanates,Sulpharsenates, Sulphantimonates, Sulphovanadates and Sulphohalides
5 : Sulphohalides
6 : Sulphosalts - Sulphostannates, Sulphogermanates,Sulpharsenates, Sulphantimonates, Sulphovanadates and Sulphohalides
5 : Sulphohalides
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 |
---|---|---|
Gcv | 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 Grechishchevite
Adamantine, Vitreous
Transparency:
Transparent
Comment:
Luster vitreous to adamantine.
Colour:
Bright or dark orange, slowly darkening to brown-orange, then black.
Streak:
deep yellow to yellow with a slight orange tint
Hardness:
2½ on Mohs scale
Hardness:
VHN25=88 - 116 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Distinct/Good
Distinct cleavage parallel to prism elongation.
Distinct cleavage parallel to prism elongation.
Density:
7.23 g/cm3 (Measured) 7.16 g/cm3 (Calculated)
Comment:
Measured on synthetic material
Optical Data of Grechishchevite
Type:
Uniaxial (+)
RI values:
nω = 2.000 nε = 2.000
Max Birefringence:
δ = 0.000
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Very High
Bireflectance:
Distinct, gray-white (R'e) to gray (R'o)
Reflectivity:
Wavelength | R1 | R2 |
---|---|---|
436nm | 19.2% | 22.8% |
460nm | 22.2% | 24.5% |
500nm | 18.9% | 21.4% |
546nm | 17.3% | 19.8% |
590nm | 16.5% | 18.8% |
620nm | 16.7% | 18.9% |
656nm | 15.9% | 18.1% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 24.5%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Gray-white
Internal Reflections:
Strong, light orange and orange
Pleochroism:
Visible
Comments:
Straw-yellow (E) to yellow (0).
Comments:
ω = > 2.0 ε = > 2.0
Chemistry of Grechishchevite
Mindat Formula:
Hg2+3S2(Br,Cl,I)2
Crystallography of Grechishchevite
Crystal System:
Tetragonal
Cell Parameters:
a = 13.2 Å, c = 6.69 Å
Ratio:
a:c = 1 : 0.507
Unit Cell V:
1,165.67 ų (Calculated from Unit Cell)
Z:
8
Morphology:
prismatic crystals, granular, to 0.3 mm; in coatings and powdery masses
Comment:
Point Group: 4/m2/m2/m, 42m,or 4mm.; Space Group: [P4/mmm, P42m, or P4mm] (by analogy to synthetic material).
Crystal Structure
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2x2x2 | 3x3x3 | 4x4x4
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
---|---|---|---|---|---|---|---|
0005919 | Grechishchevite | Pervukhina N V, Vasil'ev V I, Borisov S V, Magarill S A, Naumov D Y (2003) The crystal structure of a polymorph of Hg3S2Br1Cl.5I.5 The Canadian Mineralogist 41 1445-1453 | 2003 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.95 Å | (60) |
3.02 Å | (60) |
2.65 Å | (100) |
2.60 Å | (40) |
2.341 Å | (40) |
2.180 Å | (30wide) |
1.873 Å | (30) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
High-𝑇 alteration and/or metamorphism | |
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) | |
Stage 7: Great Oxidation Event | <2.4 |
47g : [Halogen-bearing surface weathering minerals] |
Type Occurrence of Grechishchevite
Co-Type Localities:
General Appearance of Type Material:
Occurs on fracture walls as films consisting of minute prisms and groups of equant to slightly elongate grains to 0.2 mm (Arzak deposit); also as powdery masses and as concretions of short prismatic crystals to 0.3 mm (Kadyrel occurrence).
Place of Conservation of Type Material:
Central Siberian Geological Museum, Novosibirsk, Russia, number VI-31/1 (type).
Fersman Mineralogical Museum, Moscow, Russia, number 87988-90 (type).
Mining Museum, St. Petersburg, Russia, number 503/1, 503/2 (type).
Fersman Mineralogical Museum, Moscow, Russia, number 87988-90 (type).
Mining Museum, St. Petersburg, Russia, number 503/1, 503/2 (type).
Associated Minerals at Type Locality:
Reference:
Vasil’ev, V.I., Usova, L.V., Pal’chik, N.A. (1989) Grechishchevite – Hg3S2(Br,Cl,I)2 – a new supergene mercury sulfohalide. Geologiya i Geofizika: 30: 61–69.
Synonyms of Grechishchevite
Other Language Names for Grechishchevite
Related Minerals - Strunz-mindat Grouping
2.FC. | Demicheleite-(I) | BiSI |
2.FC.05 | Djerfisherite | K6(Fe,Cu,Ni)25S26Cl |
2.FC.05 | Thalfenisite | Tl6(Fe,Ni,Cu)25S26Cl |
2.FC.05 | Owensite | (Ba,Pb)6(Cu,Fe,Ni)25S27 |
2.FC.05 | Cu-djerfisherite | K6(Cu,Fe)25S26Cl |
2.FC.05 | Zoharite | (Ba,K)6(Fe,Cu,Ni)25S27 |
2.FC.05 | Gmalimite | K6◻Fe2+24S27 |
2.FC.10 | Bartonite | K6Fe20S26S |
2.FC.10 | Chlorbartonite | K6Fe24S26(Cl,S) |
2.FC.15a | Arzakite | Hg2+3S2(Br,Cl)2 |
2.FC.15a | Corderoite | Hg2+3S2Cl2 |
2.FC.15a | Lavrentievite | Hg2+3S2(Cl,Br)2 |
2.FC.15d | Radtkeite | Hg2+3S2ICl |
2.FC.15b | Kenhsuite | Hg2+3S2Cl2 |
2.FC.20a | Capgaronnite | AgHgClS |
2.FC.20c | Perroudite | Hg5Ag4S5(I,Br)2Cl2 |
2.FC.20b | Iltisite | HgAgSCl |
2.FC.20d | Hanauerite | AgHgSI |
2.FC.25 | Demicheleite-(Br) | BiSBr |
2.FC.25 | Demicheleite-(Cl) | BiSCl |
Other Information
Notes:
Fragments blacken in 40% KOH; unaffected by HCl or HNO3.
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 Grechishchevite
mindat.org URL:
https://www.mindat.org/min-1744.html
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References for Grechishchevite
Localities for Grechishchevite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Russia (TL) | |
| Vasil’ev et al. (1989) +2 other references |
| Vasil’ev et al. (1989) +2 other references |
Quick NavTopAbout GrechishcheviteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
Kadyrel' Hg occurrence, Oorash-Khem River Valley, Uyuk Range, Pi-Khem District, Tuva, Russia