Cosalite Mineral Data

Cosalite Mineral Data +

General Cosalite Information

Chemical Formula:

Pb2Bi2S5

Composition:

Molecular Weight = 992.69 gm

Bismuth 42.10 % Bi

Lead 41.75 % Pb

Sulfur 16.15 % S

______

100.00 %

Empirical Formula:

Pb₂Bi₂S₅

Environment:

In moderate-tempurature hydrothermal deposits, contact metasomatic replacements, epithermal replacements and pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1868

Locality:

Silver Mine at Cosala, Sinaloa, Mexico. Link to MinDat.org Location Data.

Name Origin:

Named after its locality. Bjelkite is named after the Bjelke mine at Nordmark, Vermland, Sweden.

Synonym:

Bjelkite

ICSD 30780

PDF 42-1409

Cosalite Image

Images:

Cosalite

Comments: Metallic-lustered cosalite on matrix.
Location: Limestone Quarry, Hammerunterwiesenthal, Oberwiesenthal, Erzgebirge, Saxony, Germany. Scale: Picture size 8 mm.
© Thomas Witzke / Abraxas-Verlag

Cosalite Crystallography

Axial Ratios:

a:b:c =0.799:1:0.1698

Cell Dimensions:

a = 19.09, b = 23.89, c = 4.058, Z = 8; V = 1,850.69 Den(Calc)= 7.13

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pbnm

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

By Intensity(I/I_o): 3.44(1), 2.81(0.3), 3.37(0.25),

Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: [ 0 1 0] [ 2 1 0] [ 1 2 0] [ 1 3 0] [ 1 0 0] [ 1 1 0] [ 6 3 2] [ 3 0 1]

Warning: this large pop-up is very compute intensive and may not work well with some computers.

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Srikrishnan T , Nowacki W , Zeitschrift fur Kristallographie , 140 (1974) p.114-136, A redetermination of the crystal structure of cosalite, Pb2Bi2S5, Locality: Cariboo gold mines, Wells, British Columbia, Canada

Physical Properties of Cosalite

Cleavage:

[010] Good

Color:

Gray, Steel gray, Silver white.

Density:

6.4 - 6.8, Average = 6.6

Diaphaniety:

Opaque

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

2.5-3 - Finger Nail-Calcite

Luminescence:

Non-fluorescent.

Luster:

Metallic

Magnetism:

Nonmagnetic

Streak:

black

Optical Properties of Cosalite

RL Anisotrophism:

Weak but distinct in oil.

RL Color:

White with a trace of cream.

RL Pleochroism:

Weak.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Cosalite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	46.90	49.70
420 nm	46.20	49.00
440 nm	45.50	48.30
460 nm	44.70	47.50
480 nm	43.90	46.70
500 nm	43.00	46.00
520 nm	42.20	45.20
540 nm	41.50	44.50
560 nm	41.00	44.00
580 nm	40.50	43.60
600 nm	40.20	43.50
620 nm	40.10	43.40
640 nm	40.00	43.30
660 nm	40.00	43.20
680 nm	39.90	43.20
700 nm	39.90	43.10

**Calculated Relative Intensity Colors of Cosalite in Air**
Relative Intensity	0%	30%	60%	90%	100%	120%	150%	180%	210%	220%
R₁
R₂

Calculated Properties of Cosalite

Electron Density:

r_electron=5.89 gm/cc
note: r_Cosalite=7.13 gm/cc.

Fermion Index

Fermion Index = 0.09346
Boson Index = 0.90654

Photoelectric:

PE_Cosalite=1,597.07 barns/electron
U=PE_Cosalite x r_electron=9,406.16 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Cosalite is Not Radioactive

Cosalite Classification

Dana Class:

3.5.9.1 (3)Sulfides - Sulfosalts

(3.5)where 2.5 < z/y < 3 - (A+)i (A++)j [By Cz], A=metals, B=semi-metals, C=non-metals

(3.5.9)Dana Group

3.5.9.1 Cosalite Pb2Bi2S5 Pbnm 2/m 2/m 2/m

3.5.9.2 Veenite Pb2(Sb,As)2S5 P 2₁cn mm2

3.5.9.3 Dufrenoysite Pb2As2S5 P 2₁/m 2/m

Strunz Class:

II/E.34-10 II - Sulfides and sulphosalts

II/E - Sulfosalts (S : As,Sb,Bi = x) Lead-Sulfosalts (Pb-Cu/Ag) with predominant Vismut x = 6.0 - 1.6

II/E.34 - Cosalite - Galenobismuthite

II/E.34-08 Mozgovaite! PbBi4(S,Se)7 Bbmm 2/m 2/m 2/m

II/E.34-10 Cosalite Pb2Bi2S5 Pbnm 2/m 2/m 2/m

II/E.34-20 Proudite (Pb,Cu)8Bi9-10(S,Se)22 C 2/m 2/m

II/E.34-30 Weibullite Pb6Bi8(S,Se)18 P nma 2/m 2/m 2/m

II/E.34-60 Cannizzarite Pb4Bi6S13 C 2/m 2/m

II/E.34-65 Wittite Pb3Bi4(S,Se)9 P 2/m 2/m

II/E.34-70 Nordstromite Pb3CuBi7(S10Se4) P 2₁/m 2/m

II/E.34-80 Junoite Pb3Cu2Bi8(S,Se)16 C 2/m 2/m

II/E.34-85 Felbertalite! Cu2Pb6Bi8S19 C 2/m 2/m

II/E.34-90 Watkinsonite PbCu2Bi4(Se,S)8 Pm ? m

II/E.34-100 Paderaite AgPb2Cu6Bi11S22 P 2₁/m 2/m

II/E.34-110 Galenobismutite PbBi2S4 Pnam 2/m 2/m 2/m

Other Cosalite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

Search for Cosalite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Cosalite :
AA Mineral Specimens
B and L Minerals
Crystal Vaults
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Cosalite Mineral Data :

Ask about Cosalite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Cosalite Specimen Label here :

Cosalite

Pb2Bi2S5
Dana No: 3.5.9.1 Strunz No: II/E.34-10
Locality:

Notes: