Demicheleite-(Br) Mineral Data

General Demicheleite-(Br) Information

Chemical Formula:

BiSBr

Composition:

Molecular Weight = 306.48 gm

Bismuth 67.51 % Bi

Sulfur 10.15 % S

Iodine 0.83 % I

Bromine 17.47 % Br

Chlorine 4.05 % Cl

______

100.00 %

Empirical Formula:

Bi_0.99S_0.97Br_0.67Cl_0.35I_0.02

Environment:

Found in an active high-temperature fumarole at the crater rim. New structure type.

IMA Status:

Approved IMA 2007 (Dana # Added)

Locality:

La Fossa crater, Vulcano, Aeolian Islands, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for Vincenzo de Michele (b. 1936), former curator of the Section of Mineralogy of the Museo di Storia Naturale, Milan, Italy.

Synonym:

IMA2007-022

Demicheleite-(Br) Image

Images:

Demicheleite-(Br)

Comments: (SEM) image (BSE) of demicheleite. (AmMin, v93:1603).
Location: La Fossa crater, Vulcano, Aeolian Islands, Italy. Scale: See Image.
© American Mineralogist

Demicheleite-(Br) Crystallography

Axial Ratios:

a:b:c =0.8163:1:0.4093

Cell Dimensions:

a = 8.0424, b = 9.8511, c = 4.0328, Z = 4; V = 319.50 Den(Calc)= 6.37

Crystal System:

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

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

By Intensity(I/I_o): 2.909(1), 1.774(0.88), 4.22(0.68),1.865(0.63), 3.74(0.62), 2.036(0.47), 3.721(0.44), 2.429(0.43),

Physical Properties of Demicheleite-(Br)

Cleavage:

None

Color:

Dark red, Black.

Diaphaneity:

Translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Luster:

Sub Metallic

Streak:

red

Calculated Properties of Demicheleite-(Br)

Electron Density:

Bulk Density (Electron Density)=5.33 gm/cc
note: Specific Gravity of Demicheleite-(Br) =6.37 gm/cc.

Fermion Index:

Fermion Index = 0.0007618424
Boson Index = 0.9992381576

Photoelectric:

PE_{Demicheleite-(Br)}=1,319.88 barns/electron
U=PE_{Demicheleite-(Br)} x rElectron Density=7,031.12 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Demicheleite-(Br) is Not Radioactive

Demicheleite-(Br) Classification

Dana Class:

09.01.09.02 (09)Anhydrous and Hydrated Halides

(09.01)where A X

(09.01.09)Demicheleite Group

09.01.09.01 Demicheleite-(Cl)! BiSCl Pnam 2/m 2/m 2/m

09.01.09.02 Demicheleite-(Br)! BiSBr Pnam 2/m 2/m 2/m

Strunz Class:

02.FC.25 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.F - Sulfides of Arsenic, Alkalies; Sulfides with Halide, Oxide, Hydroxide, H2O

02.FC -With Cl, Br, I (halide-sulfides)

02.FC.25 Demicheleite-(Br)! BiSBr Pnam 2/m 2/m 2/m

02.FC.25 Demicheleite-(Cl)! BiSCl Pnam 2/m 2/m 2/m

Other Demicheleite-(Br) Information

References:

NAME( AmMin, v93:1603) PHYS. PROP.(AmMin, v93:1603) OPTIC PROP.(AmMin, v93:1603)

See Also:

Links to other databases for Demicheleite-(Br) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Print or Cut-and-Paste your Demicheleite-(Br) Specimen Label here :

Demicheleite-(Br)

BiSBr
Dana No: 09.01.09.02 Strunz No: 02.FC.25
Locality:

Notes: