Guyanaite
A valid IMA mineral species
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About Guyanaite
Flag of Guyana
Formula:
CrO(OH)
Colour:
Reddish brown, golden brown, greenish brown, green,
Specific Gravity:
4.67 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in 1967 by Charles Milton, Daniel E. Appleman, Edward Ching-Te Chao, Frank Cuttita, Joseph I. Dinnin, Edward J. Dwornik, Margaret Hall, Blanche L. Ingram, and Harry J. Rose, Jr. for the country where the mineral was first found: Guyana / Guiana.
Polymorph of:
The β phase of CrO(OH). As with other Cr mineral species from the Merume River locality, such as bracewellite, grimaldiite, and mcconnellite, this species is NOT universally present in every specimen and verification of each specimen is required.
A nanophase Fe analogue is known as 'proto-goethite'.
A nanophase Fe analogue is known as 'proto-goethite'.
Unique Identifiers
Mindat ID:
1783
Long-form identifier:
mindat:1:1:1783:7
Similar Names
| Cuyunite | A synonym of 'Binghamite' | |
| Kyanite | A valid IMA mineral species - grandfathered | Al2(SiO4)O |
IMA Classification of Guyanaite
Classification of Guyanaite
4.FD.10
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
D : Hydroxides with OH, without H2O; chains of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
D : Hydroxides with OH, without H2O; chains of edge-sharing octahedra
6.1.2.3
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
1 : XO(OH)
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
1 : XO(OH)
7.14.4
7 : Oxides and Hydroxides
14 : Oxides of Cr
7 : Oxides and Hydroxides
14 : Oxides of Cr
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 |
|---|---|---|
| Guy | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Guyanaite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Guyanaite
Transparency:
Translucent
Colour:
Reddish brown, golden brown, greenish brown, green,
Comment:
probably variable with particle size and degree of oxidation;
Streak:
Yellow-brown, greenish brown
Density:
4.67(14) g/cm3 (Calculated)
Optical Data of Guyanaite
Type:
Biaxial
Dispersion:
r > v extreme
Colour in reflected light:
gray with greenish tint
Internal Reflections:
strong red to yellowish brown
Pleochroism:
Weak
Comments:
brown colours
Chemistry of Guyanaite
Mindat Formula:
CrO(OH)
Elements listed:
Common Impurities:
Fe,Al,V
Crystallography of Guyanaite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 4.860(3) Å, b = 4.305(10) Å, c = 2.954(4) Å
Ratio:
a:b:c = 1.129 : 1 : 0.686
Unit Cell V:
61.80 ų (Calculated from Unit Cell)
Z:
2
Comment:
Space group is P21nm or Pnnm (LP phase); HP phase: Pnnm
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0019393 | Guyanaite | Jahn S, Wunder B, Koch-Muller M, Tarrieu L, Pohle M, Watenphul A, Taran M N (2012) Pressure-induced hydrogen bond symmetrisation in guyanaite, B-CrOOH: evidence from spectroscopy and ab initio simulations European Journal of Mineralogy 24 839-850 | 2012 | synthetic at 4.0 GPa and 600 deg C for 24 hours | 0 | 293 | |
| 0019392 | Guyanaite | Jahn S, Wunder B, Koch-Muller M, Tarrieu L, Pohle M, Watenphul A, Taran M N (2012) Pressure-induced hydrogen bond symmetrisation in guyanaite, B-CrOOH: evidence from spectroscopy and ab initio simulations European Journal of Mineralogy 24 839-850 | 2012 | synthetic at 4.0 GPa and 600 deg C for 24 hours | 0 | 293 | |
| 0019391 | Guyanaite | Jahn S, Wunder B, Koch-Muller M, Tarrieu L, Pohle M, Watenphul A, Taran M N (2012) Pressure-induced hydrogen bond symmetrisation in guyanaite, B-CrOOH: evidence from spectroscopy and ab initio simulations European Journal of Mineralogy 24 839-850 | 2012 | synthetic at 4.0 GPa and 600 deg C for 24 hours | 0 | 293 | |
| 0013341 | Guyanaite | Christensen N, Hansen P, Lehmann M S (1976) Isotope effects in the bonds of beta-CrOOH and beta-CrOOD Journal of Solid State Chemistry 19 299-304 | 1976 | synthetic | 0 | 293 | |
| 0013340 | Guyanaite | Christensen N, Hansen P, Lehmann M S (1976) Isotope effects in the bonds of beta-CrOOH and beta-CrOOD Journal of Solid State Chemistry 19 299-304 | 1976 | synthetic | 0 | 293 | |
| 0013339 | Guyanaite | Christensen N, Hansen P, Lehmann M S (1976) Isotope effects in the bonds of beta-CrOOH and beta-CrOOD Journal of Solid State Chemistry 19 299-304 | 1976 | synthetic | 0 | 293 | |
| 0013338 | Guyanaite | Christensen N, Hansen P, Lehmann M S (1976) Isotope effects in the bonds of beta-CrOOH and beta-CrOOD Journal of Solid State Chemistry 19 299-304 | 1976 | synthetic | 0 | 293 | |
| 0016640 | Guyanaite | Pernet M, Berthet-Colominas C, Alario-Franco M, Christensen A (1977) Etude par diffraction neutronique de l'oxyhydroxyde de chrome beta-CrO OH _cod_database_code 1008763 Physica Status Solidi A43 81-88 | 1977 | 0 | 293 | ||
| 0016633 | Guyanaite | Pernet M, Berthet-Colominas C, Alario-Franco M, Christensen A (1977) Etude par diffraction neutronique de l'oxyhydroxyde de chrome beta-CrO OH _cod_database_code 1008756 Physica Status Solidi A43 81-88 | 1977 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.224 Å | (vvs) |
| 2.432 Å | (vs) |
| 1.636 Å | (s) |
| 1.719 Å | (ms) |
| 1.609 Å | (ms) |
| 1.516 Å | (ms) |
| 2.524 Å | (m) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Type Occurrence of Guyanaite
General Appearance of Type Material:
microcrystalline aggregates, alluvial grains; very rarely as prismatic crystals, up to 0.1 mm
Place of Conservation of Type Material:
The Natural History Museum, London, England, 1979,136.
Geological Setting of Type Material:
In an alluvial placer deposit, in fine-grained intergrowth with other chromium oxide-hydroxide minerals
Associated Minerals at Type Locality:
Synonyms of Guyanaite
Other Language Names for Guyanaite
Common Associates
Associations Based on Photo Data:
| 1 photo of Guyanaite associated with Grimaldiite | CrO(OH) |
| 1 photo of Guyanaite associated with Bracewellite | CrO(OH) |
Related Minerals - Strunz-mindat Grouping
| 4.FD.05 | Spertiniite | Cu(OH)2 |
| 4.FD.10 | Diaspore | AlO(OH) |
| 4.FD.10 | Goethite | Fe3+O(OH) |
| 4.FD.10 | Montroseite | (V3+,Fe3+)O(OH) |
| 4.FD.10 | Tsumgallite | GaO(OH) |
| 4.FD.10 | Groutite | Mn3+O(OH) |
| 4.FD.10 | Bracewellite | CrO(OH) |
| 4.FD.15 | Manganite | Mn3+O(OH) |
| 4.FD.20 | Yttrotungstite-(Y) | YW2O7(OH) · H2O |
| 4.FD.20 | Yttrotungstite-(Ce) | CeW2O7(OH) · H2O |
| 4.FD.25 | Frankhawthorneite | Cu2Te6+O4(OH)2 |
| 4.FD.30 | 'Khinite-3T' | Pb2+Cu2+3Te6+O6(OH)2 |
| 4.FD.30 | Housleyite | Pb6CuTe6+4O18(OH)2 |
| 4.FD.30 | Khinite | Pb2+Cu2+3[Te6+O6](OH)2 |
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 Guyanaite
mindat.org URL:
https://www.mindat.org/min-1783.html
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References for Guyanaite
Localities for Guyanaite
Showing 6 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.
Antarctica | |
| Li et al. (2003) |
Finland | |
| Vuorelainen +2 other references |
Guyana | |
| Mahdia Gold Corporation |
| Geol.Soc.Amer. (1967) +1 other reference |
Russia | |
| Суставов et al. (2012) |
USA | |
| Schulze et al. (2014) |
Quick NavTopAbout GuyanaiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPronunciation Physical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Merume River, Rest of Region 8, Potaro-Siparuni Region, Guyana