Keyite Mineral Data

General Keyite Information

Chemical Formula:

Cu++3(Zn,Cu)4Cd2(AsO4)6•2(H2O)

Composition:

Molecular Weight = 1,520.19 gm

Calcium 0.26 % Ca 0.37 % CaO

Manganese 0.72 % Mn 1.04 % Mn₂O₃

Zinc 14.19 % Zn 17.67 % ZnO

Cadmium 12.57 % Cd 14.36 % CdO

Copper 15.05 % Cu 16.94 % Cu₂O

Arsenic 29.57 % As 45.36 % As₂O₅

Hydrogen 0.27 % H 2.37 % H₂O

Oxygen 27.36 % O

______ ______

100.00 % 98.11 % = TOTAL OXIDE

Empirical Formula:

Cu_3.6Zn_3.3Cd_1.7Mn³⁺_0.2Ca_0.1(AsO₄)₆•2(H₂O)

Environment:

Secondary mineral in the oxidized zone of a dolostone-hosted hydrothermal polymetallic ore deposit.

IMA Status:

Approved IMA 1977

Locality:

Tsumeb, Namibia. Link to MinDat.org Location Data.

Name Origin:

Named for Charles Locke Key (1935-), Canton, Connecticut, USA, American mineral dealer who furnished the first specimens.

Name Pronunciation:

Keyite

Synonym:

ICSD 82482

PDF 29-256

Keyite Image

Images:

Keyite

Comments: Brilliant blue keyite crystals on a matrix of white, metallic suflide-arsenide ore.
Location: Tsumeb, Namibia. Scale: 0.9 x 0.7 x 0.7 cm.
© Rob Lavinsky

Keyite Crystallography

Axial Ratios:

a:b:c =0.9118:1:0.5352

Cell Dimensions:

a = 11.654, b = 12.78, c = 6.84, Z = 2; beta = 99.11° V = 1,005.89 Den(Calc)= 5.02

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: I2/a

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

By Intensity(I/I_o): 2.795(1), 2.876(0.9), 3.29(0.9),

Physical Properties of Keyite

Cleavage:

{001} Good

Color:

Azure.

Density:

4.95

Diaphaneity:

Translucent

Habit:

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

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

3.5-4 - Copper Penny-Fluorite

Streak:

light blue

Optical Properties of Keyite

Gladstone-Dale:

CI meas= 0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.031 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1663,KPDmeas= 0.1687,KC= 0.1717
Ncalc = 1.85 - 1.86

Optical Data:

Biaxial (?), a=1.8, g=1.87, bire=0.0700

Pleochroism (x):

pale blue.

Pleochroism (y):

greenish blue.

Pleochroism (z):

deep blue.

Calculated Properties of Keyite

Electron Density:

Bulk Density (Electron Density)=4.57 gm/cc
note: Specific Gravity of Keyite =4.95 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Keyite= 67.96 barns/electron
U=PE_Keyite x rElectron Density= 310.71 barns/cc.

Radioactivity:

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

Keyite Classification

Dana Class:

38.03.08.01 (38)Anhydrous Phosphates, etc

(38.03)(A+ B++)3 (XO4)2

(38.03.08)Dana Group

38.03.08.01 Keyite Cu3(Zn,Cu)4Cd2(AsO4)6•2(H2O) I2/a 2/m

Strunz Class:

08.CA.50 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CA -With small and large/medium cations

08.CA.50 Keyite Cu3(Zn,Cu)4Cd2(AsO4)6•2(H2O) I2/a 2/m

Other Keyite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic4)

See Also:

Links to other databases for Keyite :
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
15 - WWW-MINCRYST

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

Keyite

Cu++3(Zn,Cu)4Cd2(AsO4)6•2(H2O)
Dana No: 38.03.08.01 Strunz No: 08.CA.50
Locality:

Notes:

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