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 % P₂O₅

Hydrogen 0.14 % H 1.22 % H₂O

Lead 70.19 % Pb 75.61 % PbO

Oxygen 18.43 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Pb₅(CrO₄)₂(PO₄)₂•(H₂O)

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

Comments: Orange embreyite crystals on matrix.
Location: Cumbria, England. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

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

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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:

PE_Embreyite=1,272.31 barns/electron
U=PE_Embreyite x rElectron 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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Print or Cut-and-Paste your Embreyite Specimen Label here :

Embreyite

Pb5(CrO4)2(PO4)2•(H2O)
Dana No: 43.03.02.01 Strunz No: 07.FC.20
Locality:

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