Embreyite Mineral Data
General Embreyite Information
Chemical Formula:
Pb5(CrO4)2(PO4)2•(H2O)
Composition:
Molecular Weight = 1,475.95 gm
Chromium 7.05 % Cr 13.55 % CrO3
Phosphorus 4.20 % P 9.62 % P2 O5
Hydrogen 0.14 % H 1.22 % H2 O
Lead 70.19 % Pb 75.61 % PbO
Oxygen 18.43 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Pb5 (CrO4 )2 (PO4 )2 •(H2 O)
IMA Status:
Approved IMA 1972
Locality:
Berezov, Ekaterinburg (Sverdlovsk), Ural Mts, Russia Link to MinDat.org Location Data.
Name Origin:
Named for P. G. Embry
Name Pronunciation:
Embreyite + Pronunciation
Embreyite Image
Images:
Embreyite Crystallography
Axial Ratios:
a:b:c =1.7308:1:1.2659
Cell Dimensions:
a = 9.755, b = 5.636, c = 7.135, Z = 1; beta = 103.08° V = 382.10 Den(Calc)= 6.41
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /m
X Ray Diffraction:
By Intensity(I/Io ): 3.167(1), 2.818(0.6), 4.751(0.6),
Physical Properties of Embreyite
Cleavage:
None
Color:
Orange.
Density:
6.45
Diaphaneity:
Transparent to Translucent
Fracture:
Brittle - Uneven - Very brittle fracture producing uneven fragments.
Hardness:
3.5 - Copper Penny
Luster:
Earthy (Dull)
Streak:
yellow
Optical Properties of Embreyite
Gladstone-Dale:
CI meas = -0.208 (Poor) - where the CI = (1-KPDmeas /KC ) CI calc = -0.216 (Poor) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2038,KPDmeas = 0.2026,KC = 0.1677 Ncalc = 2.07 - 2.08
Optical Data:
Biaxial (-), a=2.2, b=2.36, g=2.36, bire=0.1600, 2V(Calc)=0, 2V(Meas)=0-10.
Calculated Properties of Embreyite
Electron Density:
Bulk Density (Electron Density)=5.47 gm/cc note: Specific Gravity of Embreyite =6.45 gm/cc.
Fermion Index:
Fermion Index = 0.16 Boson Index = 0.84
Photoelectric:
PEEmbreyite =1,272.31 barns/electronU=PEEmbreyite x r Electron Density=6,961.23 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Embreyite is Not Radioactive
Embreyite Classification
Dana Class:
43.03.02.01 (43) Compound Phosphates, etc.
(43.03) (Hydrated Normal Compound Anions)
(43.03.02) Dana Group
43.03.02.01 Embreyite Pb5(CrO4)2(PO4)2•(H2O) P 21 /m 2/m
43.03.02.02 Cassedanneite Pb5(VO4)2(CrO4)2•(H2O) A2/m 2/m
Strunz Class:
07.FC.20 07 - SULFATES (SELENATES, TELLURATES)
07.F - Chromates
07.FC -With PO4, AsO4, SiO4
07.FC.20 Cassedanneite Pb5(VO4)2(CrO4)2•(H2O) A2/m 2/m
07.FC.20 Embreyite Pb5(CrO4)2(PO4)2•(H2O) P 21 /m 2/m
Other Embreyite Information
References:
PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Embreyite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
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Embreyite
Pb5(CrO4)2(PO4)2•(H2O)
Dana No: 43.03.02.01 Strunz No: 07.FC.20
Locality:
Notes:
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