Theisite Mineral Data

General Theisite Information

Chemical Formula:

Cu5Zn5[(As+++++,Sb+++++)O4]2(OH)14

Composition:

Molecular Weight = 1,184.04 gm

Zinc 27.61 % Zn 34.37 % ZnO

Copper 26.83 % Cu 33.59 % CuO

Antimony 5.14 % Sb 6.83 % Sb₂O₅

Arsenic 9.49 % As 14.56 % As₂O₅

Hydrogen 1.19 % H 10.65 % H₂O

Oxygen 29.73 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Cu₅Zn₅(AsO₄)_1.5(SbO₄)_0.5(OH)₁₄

Environment:

Found in a uranium prospect.

IMA Status:

Approved IMA 1982

Locality:

Durango, La Plata, County, Colorade, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Nicholas J. Theis, Geologist, Bendix Corp., who discovered the orignal sample.

Name Pronunciation:

Theisite

Theisite Image

Images:

Theisite

Comments: Pale blue pearly theisite scattered on matrix.
Location: Grand Junction, Mesa County, Colorado, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Theisite Crystallography

Axial Ratios:

a:b:c =1.1547:1:2.1016

Cell Dimensions:

a = 8.225, b = 7.123, c = 14.97, Z = 2; V = 877.04 Den(Calc)= 4.48

Crystal System:

Orthorhombic Space Group: pseudo-HEX

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

By Intensity(I/I_o): 3.741(1), 2.534(0.9), 14.973(0.9),

Physical Properties of Theisite

Cleavage:

{001} Perfect

Color:

Blue green, Green.

Density:

4.3

Diaphaneity:

Translucent

Fracture:

Sectile - Curved shavings or scrapings produced by a knife blade, (e.g. graphite).

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Hardness:

1.5 - Between Talc and Gypsum

Optical Properties of Theisite

Gladstone-Dale:

CI meas= 0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.048 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.173,KPDmeas= 0.1802,KC= 0.1817
Ncalc = 1.78 - 1.81

Optical Data:

Biaxial (-), a=1.755, b=1.785, g=1.785, bire=0.0300, 2V(Calc)=0, 2V(Meas)=0.

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Theisite

Electron Density:

Bulk Density (Electron Density)=4.07 gm/cc
note: Specific Gravity of Theisite =4.30 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Theisite= 48.41 barns/electron
U=PE_Theisite x rElectron Density= 196.91 barns/cc.

Radioactivity:

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

Theisite Classification

Dana Class:

41.01.02.01 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen

(41.01)where (A++)m (XO4)p Zq, with m:p>4:1

(41.01.02)Dana Group

41.01.02.01 Theisite Cu5Zn5[(As,Sb)O4]2(OH)14 pseudo-HEX Ortho

41.01.02.02 Sabelliite! Cu2Zn(As,Sb)O4(OH)3 P 3 3

Strunz Class:

08.BE.75 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BE -With only medium-sized cations, (OH, etc.):RO4 > 2:1

08.BE.75 Theisite Cu5Zn5[(As,Sb)O4]2(OH)14 pseudo-HEX Ortho

Other Theisite Information

References:

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

See Also:

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

Theisite

Cu5Zn5[(As+++++,Sb+++++)O4]2(OH)14
Dana No: 41.01.02.01 Strunz No: 08.BE.75
Locality:

Notes:

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