Larosite Mineral Data

General Larosite Information

Chemical Formula:

(Cu,Ag)21(Pb,Bi)2S13

Composition:

Molecular Weight = 2,256.15 gm

Copper 53.51 % Cu

Silver 9.56 % Ag

Bismuth 9.26 % Bi

Lead 9.18 % Pb

Sulfur 18.48 % S

______

100.00 %

Empirical Formula:

Cu₁₉Ag₂PbBiS₁₃

Environment:

Central portion of a vein with chalcocite and stromeyerite.

IMA Status:

Approved IMA 1972

Locality:

Foster mine, Cobalt, Ontario, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for Fred LaRose, a discoverer of silver ore at Cobalt.

Name Pronunciation:

Larosite

Synonym:

IMA1971-014

Larosite Crystallography

Axial Ratios:

a:b:c =0.9217:1:0.4856

Cell Dimensions:

a = 22.15, b = 24.03, c = 11.67, Z = 10; V = 6,211.53 Den(Calc)= 6.03

Crystal System:

Orthorhombic Space Group: Unk

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

By Intensity(I/I_o): 1.982(1), 2.917(0.9), 2.846(0.6),

Physical Properties of Larosite

Color:

Black.

Diaphaneity:

Opaque

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

3-3.5 - Calcite-Copper Penny

Luster:

Metallic

Optical Properties of Larosite

RL Anisotrophism:

Moderate, in gray and greenish buff.

RL Color:

Whitish buff.

RL Pleochroism:

Weak.

Calculated Properties of Larosite

Electron Density:

Bulk Density (Electron Density)=5.44 gm/cc
note: Specific Gravity of Larosite =6.03 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Larosite= 371.54 barns/electron
U=PE_Larosite x rElectron Density=2,021.76 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Larosite is Not Radioactive

Larosite Classification

Dana Class:

02.16.09.01 (02)Sulfides - Including Selenides and Tellurides

(02.16)with miscellaneous formulae

(02.16.09)Dana Group

02.16.09.01 Larosite (Cu,Ag)21(Pb,Bi)2S13 Unk Ortho

Strunz Class:

02.LB.35 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.L - Unclassified Sulfosalts

02.LB -With essential Pb

02.LB.35 Larosite (Cu,Ag)21(Pb,Bi)2S13 Unk Ortho

Other Larosite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

See Also:

Links to other databases for Larosite :
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 Larosite Specimen Label here :

Larosite

(Cu,Ag)21(Pb,Bi)2S13
Dana No: 02.16.09.01 Strunz No: 02.LB.35
Locality:

Notes:

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