Embreyite
A valid IMA mineral species
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About Embreyite
Formula:
Pb5(CrO4)2(PO4)2 · H2O
Colour:
Dull orange
Lustre:
Resinous, Dull
Hardness:
3½
Specific Gravity:
6.45
Crystal System:
Monoclinic
Name:
Named in honor of Peter Godwin Embrey (1929-2010), British Museum. His achievements in the science included the reprint of Greg and Lettsom's British Mineralogy in 1977, and Minerals of Cornwall and Devon published in 1987.
See also https://www.mindat.org/mesg-631485.html for more info on Peter Embrey.
See also https://www.mindat.org/mesg-631485.html for more info on Peter Embrey.
Type Locality:
Unique Identifiers
Mindat ID:
1373
Long-form identifier:
mindat:1:1:1373:0
GUID
(UUID V4):
(UUID V4):
e0fb1f83-aa1f-4fe5-a1d2-acfc6a0a2c10
IMA Classification of Embreyite
Approved
Approval year:
1971
First published:
1972
Classification of Embreyite
7.FC.20
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
C : With PO4, AsO4, SiO4
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
C : With PO4, AsO4, SiO4
43.3.2.1
43 : COMPOUND PHOSPHATES, ETC.
3 : Hydrated Normal Compound Phosphates, etc·
43 : COMPOUND PHOSPHATES, ETC.
3 : Hydrated Normal Compound Phosphates, etc·
22.5.2
22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate
22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate
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 |
---|---|---|
Emb | 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 Embreyite
Resinous, Dull
Transparency:
Transparent, Translucent
Comment:
Dull to resinous
Colour:
Dull orange
Comment:
Various shades of orange.
Streak:
Yellow
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
6.45(12) g/cm3 (Measured) 6.564 g/cm3 (Calculated)
Optical Data of Embreyite
Type:
Biaxial (-)
RI values:
nα = 2.200 nβ = 2.360 nγ = 2.360
Max Birefringence:
δ = 0.160
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
Dispersion:
relatively strong
Optical Extinction:
Y = b.
Pleochroism:
Weak
Comments:
X = honey-yellow; Y = Z = amber.
Chemistry of Embreyite
Mindat Formula:
Pb5(CrO4)2(PO4)2 · H2O
Crystallography of Embreyite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 9.802(16) Å, b = 5.603(9) Å, c = 7.649(12) Å
β = 114.85°
β = 114.85°
Ratio:
a:b:c = 1.749 : 1 : 1.365
Unit Cell V:
381.2 ų
Z:
1
Twinning:
Multiple twinning and 60° sector zoning observed optically.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.167 Å | (100) |
4.751 Å | (60) |
2.818 Å | (60) |
1.917 Å | (45) |
3.563 Å | (32) |
2.213 Å | (32) |
2.187 Å | (31) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47c : [Carbonates, phosphates, borates, nitrates] | |
47e : [Vanadates, chromates, manganates] |
Type Occurrence of Embreyite
General Appearance of Type Material:
Thick botryoidal crusts consisting of tiny tabular crystals with the plane of flattening approximately normal to the surface of the crust.
Place of Conservation of Type Material:
The Natural History Museum, London, England, number 39316.
Associated Minerals at Type Locality:
Reference:
Williams, S. A. (1972) Embreyite, a new mineral from Berezov, Siberia. Mineralogical Magazine: 38: 790-793.
Synonyms of Embreyite
Other Language Names for Embreyite
Common Associates
Associated Minerals Based on Photo Data:
29 photos of Embreyite associated with Pyromorphite | Pb5(PO4)3Cl |
23 photos of Embreyite associated with Crocoite | PbCr6+O4 |
15 photos of Embreyite associated with Vauquelinite | Pb2Cu(CrO4)(PO4)(OH) |
3 photos of Embreyite associated with Mimetite | Pb5(AsO4)3Cl |
2 photos of Embreyite associated with Trippkeite | Cu2+As3+2O4 |
1 photo of Embreyite associated with Cerussite | PbCO3 |
1 photo of Embreyite associated with Bindheimite | Pb2Sb2O6O |
1 photo of Embreyite associated with Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
1 photo of Embreyite associated with Shattuckite | Cu5(Si2O6)2(OH)2 |
1 photo of Embreyite associated with Quartz | SiO2 |
Related Minerals - Strunz-mindat Grouping
7.FC.05 | Vauquelinite | Pb2Cu(CrO4)(PO4)(OH) |
7.FC.10 | Fornacite | Pb2Cu(CrO4)(AsO4)(OH) |
7.FC.10 | Molybdofornacite | Pb2Cu(MoO4,CrO4)(AsO4,PO4)(OH) |
7.FC.15 | Hemihedrite | Pb10Zn(CrO4)6(SiO4)2(OH)2 |
7.FC.15 | Iranite | Pb10Cu(CrO4)6(SiO4)2(OH)2 |
7.FC.15 | Raygrantite | Pb10Zn(SO4)6(SiO4)2(OH)2 |
7.FC.20 | Cassedanneite | Pb5(CrO4)2(VO4)2 · H2O |
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 Embreyite
mindat.org URL:
https://www.mindat.org/min-1373.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Embreyite
Localities for Embreyite
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.
France | |
| Cuchet et al. (2008) |
Germany | |
| Leonhardt et al. (1991) +1 other reference |
Russia (TL) | |
| Williams (1972) |
Pavel.M. Kartashov (n.d.) | |
South Africa | |
| Southwood et al. (1986) |
Cairncross et al. (1995) | |
| SAMS (South African Micromount Society) |
USA | |
| Möckel (2018) |
Quick NavTopAbout EmbreyiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Callenberg, Zwickau District, Saxony, Germany