General Lafossaite Information Chemical Formula: |
Tl(Cl,Br) |
Composition: |
Molecular Weight = 252.93 gm |
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Thallium 82.99 % Tl 86.24 % Tl2O |
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Bromine 6.07 % Br 6.07 % Br |
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- %
Br -0.61 % -O=Br2 |
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Chlorine 10.95 % Cl 10.95 % Cl |
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- %
Cl -2.47 % -O=Cl2 |
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______ ______ |
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100.00 % 100.17 % = TOTAL OXIDE |
Empirical Formula: |
Tl1.02Cl0.78Br0.19 |
Environment: |
Occurs as a drusy coating on one surface of a single specimen collected from an active fumarole. Sal ammoniac group. |
IMA Status: |
Approved IMA 2003 (Dana # Added) |
Locality: |
La Fossa crater, Vulcano, Italy Link to MinDat.org Location Data. |
Name Origin: |
Named for the locality. |
| | Search for Lafossaite Images
Images:
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| | Lafossaite Crystallography Cell Dimensions: |
a = 3.8756, Z = 1; V = 58.21 Den(Calc)= 7.21 |
Crystal System: |
Isometric - HexoctahedralH-M Symbol (4/m 3 2/m) Space Group: P m3m |
X Ray Diffraction: |
By Intensity(I/Io): 2.745(1)(110 ), 3.887(0.8)(100 ), 1.583(0.7)(211 ),2.237(0.55)(111 ), 1.937(0.5)(200 ), 1.733(0.45)(210 ), 1.226(0.25)(310 ), 1.37(0.25)(220 ), 1.291(0.2)(221,300), |
| Physical Properties of Lafossaite Cleavage: |
None |
Color: |
Grayish brown. |
Diaphaneity: |
Translucent |
Fracture: |
Malleable - Deforms rather than breaking apart with a hammer. |
Habit: |
Cubic Crystals - Occurs as cubic shaped crystals. |
Habit: |
Subhedral Crystals - Occurs as crystals which tend to exhibit a recognizable crystal shape. |
Hardness: |
3-4 - Calcite-Fluorite |
Luster: |
Resinous - Greasy |
Streak: |
resinous off white |
| Optical Properties of Lafossaite Gladstone-Dale: |
CI calc= -0.193 (Poor) - where the CI = (1-KPDcalc/KC) |
KPDcalc= 0.1753,KC= 0.1469 Ncalc = 2.06 Optical Data: |
Isotropic, n=2.264. |
RL Anisotrophism: |
None. |
RL Bireflectance: |
None. |
RL Color: |
White with white internal reflections. |
RL Pleochroism: |
None. |
Reflectivity |
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| Calculated Properties of Lafossaite Electron Density: |
Bulk Density (Electron Density)=5.88 gm/cc |
note: Specific Gravity of Lafossaite =7.21 gm/cc. Fermion Index: |
Fermion Index = 0 |
Boson Index = 1 Photoelectric: |
PELafossaite =1,502.75 barns/electron |
U=PELafossaite x rElectron Density=8,840.18 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Lafossaite is Not Radioactive | Lafossaite Classification Dana Class: |
09.01.03.02 (09)Anhydrous and Hydrated Halides |
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(09.01)where A X |
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(09.01.03)Dana Group |
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Strunz Class: |
03.AA.25 03 - HALIDES |
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03.A - Simple Halides, Without H2O |
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03.AA -M:X = 1:1, 2:3, 3:5, etc. |
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| Other Lafossaite Information References: |
NAME( AmMin, v91, p1455) PHYS. PROP.(AmMin, v91, p1455) OPTIC PROP.(AmMin, v91, p1455) |
See Also: |
Links to other databases for Lafossaite : |
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 Search for Lafossaite using: Visit our Advertisers for Lafossaite : A Bijoux Google Search for LafossaiteAdam's Minerals Google Search for Lafossaite Cape Minerals Google Search for Lafossaite Dakota Matrix Minerals Google Search for Lafossaite Excalibur Mineral Corp. Google Search for Lafossaite Exceptional Minerals Google Search for Lafossaite John Betts Fine Minerals Search for Lafossaite McDougall Minerals Google Search for Lafossaite Mineral News Website Link Rock and Mineral Shows Google Search for Lafossaite Weinrich Minerals, Inc. Google Search for Lafossaite Ask about Lafossaite here : Print or Cut-and-Paste your Lafossaite Specimen Label here :
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