Keystoneite
A valid IMA mineral species
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About Keystoneite
Formula:
Mg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Colour:
Golden yellow
Lustre:
Adamantine
Specific Gravity:
4.4 (Calculated)
Crystal System:
Hexagonal
Member of:
Name:
For the type locality.
Ni-analogue of kinichilite and zemannite. The Ni-Fe-analogue of ilirneyite.
Chemically and structurally related to wortupaite.
Chemically and structurally related to wortupaite.
Unique Identifiers
Mindat ID:
2192
Long-form identifier:
mindat:1:1:2192:6
IMA Classification of Keystoneite
Classification of Keystoneite
4.JM.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
M : Tellurites without additional anions, with H2O
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
M : Tellurites without additional anions, with H2O
34.3.2.3
34 : SELENITES, TELLURITES AND SULFITES
3 : A2(XO3)3·xH2O
34 : SELENITES, TELLURITES AND SULFITES
3 : A2(XO3)3·xH2O
28.3.28
28 : Selenites, Selenates, Tellurites, and Tellurates
3 : Tellurites
28 : Selenites, Selenates, Tellurites, and Tellurates
3 : Tellurites
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 |
|---|---|---|
| Kys | 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 Keystoneite
Adamantine
Transparency:
Translucent
Colour:
Golden yellow
Streak:
Pale yellow-green
Density:
4.4 g/cm3 (Calculated)
Optical Data of Keystoneite
Type:
Uniaxial (+)
RI values:
nω = 1.85(1) nε = 1.99(1)
Max. Birefringence:
δ = 0.140
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate
Chemistry of Keystoneite
Mindat Formula:
Mg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Element Weights:
Crystallography of Keystoneite
Crystal System:
Hexagonal
Class (H-M):
6 - Pyramidal
Space Group:
P63
Cell Parameters:
a = 9.3667(5) Å, c = 7.6173(3) Å
Ratio:
a:c = 1 : 0.813
Unit Cell V:
578.77 ų
Z:
2
Morphology:
Acicular hexagonal crystals, parallel aggregates and radiating sprays.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.12 Å | (90) |
| 4.05 Å | (80) |
| 2.952 Å | (50) |
| 2.838 Å | (50) |
| 2.774 Å | (100) |
| 1.720 Å | (60) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Keystoneite
Place of Conservation of Type Material:
Canadian Museum of Nature, Ottawa, Canada 56561
Geological Setting of Type Material:
Oxidation zone of a complex polymetallic hydrothermal deposit.
Synonyms of Keystoneite
Other Language Names for Keystoneite
Relationship of Keystoneite to other Species
Member of:
Other Members of Zemannite Group:
| Ilirneyite | Mg0.5ZnMn3+(Te4+O3)3 · 4.5H2O | Hex. 6/m : P63/m |
| Kinichilite | Mg0.5Mn2+Fe3+(Te4+O3)3 · 4.5H2O | Hex. 6/m : P63/m |
| Zemannite | Mg0.5ZnFe3+(Te4+O3)3 · 4.5H2O | Trig. 3 : P3 |
Common Associates
Associations Based on Photo Data:
| 5 photos of Keystoneite associated with Choloalite | (Cu,Sb)3(Pb,Ca)3(TeO3)6Cl |
| 5 photos of Keystoneite associated with Quartz | SiO2 |
| 1 photo of Keystoneite associated with Hessite | Ag2Te |
| 1 photo of Keystoneite associated with Native Gold | Au |
| 1 photo of Keystoneite associated with Altaite | PbTe |
| 1 photo of Keystoneite associated with Melonite | NiTe2 |
| 1 photo of Keystoneite associated with Petzite | Ag3AuTe2 |
Related Minerals - Strunz-mindat Grouping
| 4.JM. | Wortupaite | MgNi2+2(Te4+O3)3 · 3H2O |
| 4.JM. | Rudolfhermannite | Fe3+2(Te4+O3)3(H2O) |
| 4.JM.05 | Zemannite | Mg0.5ZnFe3+(Te4+O3)3 · 4.5H2O |
| 4.JM.05 | Kinichilite | Mg0.5Mn2+Fe3+(Te4+O3)3 · 4.5H2O |
| 4.JM.05 | Ilirneyite | Mg0.5ZnMn3+(Te4+O3)3 · 4.5H2O |
| 4.JM.10 | Emmonsite | Fe3+2(TeO3)3 · 2H2O |
| 4.JM.10 | Blakeite | Fe3+2[TeO3]3 (?) |
| 4.JM.15 | Graemite | Cu[TeO3] · H2O |
| 4.JM.20 | Telluromandarinoite | Fe3+2Te3O9 · 6H2O |
| 4.JM.20 | Teineite | Cu2+(Te4+O3) · 2H2O |
| 4.JM.25 | Millsite | Cu2+(Te4+O3) · 2H2O |
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 Keystoneite
mindat.org URL:
https://www.mindat.org/min-2192.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Keystoneite
Localities for Keystoneite
Showing 5 localities.
symbol to view information about a locality.
The 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.
Armenia | |
| Pavel M. Kartashov analytical data (2003) |
Mexico | |
| Collected by and in the collection of ... |
USA | |
| Roberts et al. (1994) +1 other reference |
| Eckel et al. (1997) +2 other references |
| Eckel et al. (1997) |
Quick NavTopAbout KeystoneiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
McAlpine Mine, Peñon Blanco Peak, Coulterville Mining District, Tuolumne County, California, USA