Hephaistosite Mineral Data

General Hephaistosite Information

Chemical Formula:

TlPb2Cl5

Composition:

Molecular Weight = 793.05 gm

Thallium 24.23 % Tl 27.07 % Tl₂O₃

Lead 52.51 % Pb 54.54 % Pb₂O

Bromine 1.41 % Br 1.41 % Br

- % Br -0.14 % -O=Br₂

Chlorine 21.68 % Cl 21.68 % Cl

- % Cl -4.89 % -O=Cl₂

Fluorine 0.17 % F 0.17 % F

- % F -0.07 % -O=F₂

______ ______

100.00 % 99.77 % = TOTAL OXIDE

Empirical Formula:

Tl_0.94Pb_2.01Cl_4.85Br_0.14F_0.07

Environment:

Found in a high-temperature fumarole (~400°C) at the rim of La Fossa crater. Isostructural with challacolloite.

IMA Status:

Approved IMA 2006 (Dana # Added)

Locality:

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

Name Origin:

Named for the Greek god of fire, Hephaistos (Hephaestus), whose workshops were alleged located at the locality (Vulcano).

Synonym:

IMA2006-043

Hephaistosite Image

Images:

Hephaistosite

Comments: BSE image of hephaistosite crystals (CanMin, v43:701).
Location: Rim of La Fossa crater, Vulcano Island, Aeolian archipelago, Sicily, Italy. Scale: Crystal length 0.5 mm.
© Canadian Mineralogist

Hephaistosite Crystallography

Axial Ratios:

a:b:c =1.1295:1:1.5773

Cell Dimensions:

a = 8.9477, b = 7.9218, c = 12.4955, Z = 4; beta = 90.092° V = 885.70 Den(Calc)= 5.95

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 3.696(1), 3.971(0.83), 2.109(0.45),2.569(0.42), 1.848(0.41), 2.851(0.38), 2.236(0.25), 2.273(0.22),

Physical Properties of Hephaistosite

Color:

Pale yellow.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Optical Properties of Hephaistosite

Gladstone-Dale:

CI calc= -0.954 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1681,KC= 0.086
Ncalc = 1.51

Optical Data:

Biaxial (?), a=2

Calculated Properties of Hephaistosite

Electron Density:

Bulk Density (Electron Density)=4.94 gm/cc
note: Specific Gravity of Hephaistosite =5.95 gm/cc.

Fermion Index:

Fermion Index = 0.11
Boson Index = 0.89

Photoelectric:

PE_{Hephaistosite}=1,404.32 barns/electron
U=PE_{Hephaistosite} x rElectron Density=6,931.50 barns/cc.

Radioactivity:

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

Hephaistosite Classification

Dana Class:

11.05.08.02 (11)Halide Complexes; Alumino-fluorides

(11.05)where (A)m B (X)6

(11.05.08)Challacolloite Group

11.05.08.01 Challacolloite! KPb2Cl5 P 2₁/c 2/m

11.05.08.02 Hephaistosite! TlPb2Cl5 P 2₁/c 2/m

11.05.08.03 Steropesite! Tl3BiCl6 Cc m

11.05.08.04 Panichiite! (NH4)2SnCl6 Fm3m 4 3m

Strunz Class:

03.AA.55 03 - HALIDES

03.A - Simple Halides, Without H2O

03.AA -M:X = 1:1, 2:3, 3:5, etc.

03.AA.55 Challacolloite! KPb2Cl5 P 2₁/c 2/m

03.AA.55 Hephaistosite! TlPb2Cl5 P 2₁/c 2/m

Other Hephaistosite Information

References:

NAME( AmMin, v94:399) PHYS. PROP.(AmMin, v94:399) OPTIC PROP.(AmMin, v94:399)

See Also:

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

Hephaistosite

TlPb2Cl5
Dana No: 11.05.08.02 Strunz No: 03.AA.55
Locality:

Notes:

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