Hemihedrite Mineral Data
General Hemihedrite Information
Chemical Formula:
Pb10Zn(CrO4)6(SiO4)2F2
Composition:
Molecular Weight = 3,055.52 gm
Zinc 2.14 % Zn 2.66 % ZnO
Chromium 10.21 % Cr 19.64 % CrO3
Silicon 1.84 % Si 3.93 % SiO2
Lead 67.81 % Pb 73.05 % PbO
Oxygen 16.76 % O
Fluorine 1.24 % F 1.24 % F
- %
F -0.52 % -O=F2
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Pb10 Zn(CrO4 )6 (SiO4 )2 F2
Environment:
Secondary lead mineral from oxidized primary minerals.
IMA Status:
Approved IMA 1967
Locality:
Florence mine, Pinal County and Pack Rat claim, Whickenburg, Maricopa County, Arizona, USA. Link to MinDat.org Location Data.
Name Origin:
Named for its hemihedral crystal morphology.
Name Pronunciation:
Hemihedrite + Pronunciation
Synonym:
ICSD 15175
PDF 24-1457
Hemihedrite Image
Images:
Images:
Hemihedrite Phoenicochroite
Comments: Yellow hemihedrite crystals to 1 mm within pockets of dark red phoenicochroite crystalline aggregates on matrix.
Location: Pack Rat claim, Maricopa Co., Arizona, USA.
Scale: Picture size 1.5 cm.
© Tom Loomis / Dakota Matrix
Hemihedrite Crystallography
Axial Ratios:
a:b:c =0.8299:1:0.9473
Cell Dimensions:
a = 9.497, b = 11.443, c = 10.841, Z = 1; alpha = 120.5°, beta = 92.1°, gamma = 55.84° V = 839.42 Den(Calc)= 6.04
Crystal System:
Triclinic - Pinacoidal H-M Symbol ( 1 ) Space Group: P1
X Ray Diffraction:
By Intensity(I/Io ): 3.302(1), 3.11(0.69), 3.163(0.69),
Physical Properties of Hemihedrite
Color:
Orange, Brown, Black.
Density:
6.42
Hardness:
3 - Calcite
Luster:
Vitreous (Glassy)
Streak:
saffron
Optical Properties of Hemihedrite
Gladstone-Dale:
CI meas = -0.203 (Poor) - where the CI = (1-KPDmeas /KC ) CI calc = -0.199 (Poor) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2109,KPDmeas = 0.2116,KC = 0.1759 Ncalc = 2.13
Optical Data:
Biaxial (+), a=2.105, b=2.32, g=2.65, bire=0.5450, 2V(Calc)=88, 2V(Meas)=88. Dispersion strong.
Calculated Properties of Hemihedrite
Electron Density:
Bulk Density (Electron Density)=5.46 gm/cc note: Specific Gravity of Hemihedrite =6.44 gm/cc.
Fermion Index:
Fermion Index = 0.16 Boson Index = 0.84
Photoelectric:
PEHemihedrite =1,231.05 barns/electronU=PEHemihedrite x r Electron Density=6,725.33 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Hemihedrite is Not Radioactive
Hemihedrite Classification
Dana Class:
36.01.01.02 (36) Compound Chromates
(36.01) with miscellaneous formulae
(36.01.01) Dana Group
36.01.01.01 Iranite Pb10Cu(CrO4)6(SiO4)2(F,OH)2 P1 1
36.01.01.02 Hemihedrite Pb10Zn(CrO4)6(SiO4)2F2 P1 1
Strunz Class:
07.FC.15 07 - SULFATES (SELENATES, TELLURATES)
07.F - Chromates
07.FC -With PO4, AsO4, SiO4
07.FC.15 Hemihedrite Pb10Zn(CrO4)6(SiO4)2F2 P1 1
07.FC.15 Iranite Pb10Cu(CrO4)6(SiO4)2(F,OH)2 P1 1
Other Hemihedrite 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 Hemihedrite :
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
15 - WWW-MINCRYST
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Hemihedrite
Pb10Zn(CrO4)6(SiO4)2F2
Dana No: 36.01.01.02 Strunz No: 07.FC.15
Locality:
Notes:
Dakota Matrix
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