Kokchetavite Mineral Data

General Kokchetavite Information

Chemical Formula:

KAlSi3O8

Composition:

Molecular Weight = 278.33 gm

Potassium 14.05 % K 16.92 % K₂O

Aluminum 9.69 % Al 18.32 % Al₂O₃

Silicon 30.27 % Si 64.76 % SiO₂

Oxygen 45.99 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

KAlSi₃O₈

Environment:

Micrometer-size inclusions in clinopyroxene and garnet in a garnet-pyroxene rock. Ultrahigh pressure metastable polymorph of K-feldspar.

IMA Status:

Approved IMA 2004 (Dana # Added)

Locality:

Kumdy-Kul, Kokchetav, Kazakhstan. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Synonym:

IMA2004-011

Kokchetavite Image

Images:

Kokchetavite

Comments: Fragment of eclogite containing kokchetavite which occurs as inclusions in clinopyroxene and garnet (see inset BSE images).
Location: Kumde-Kul Area, Kokchetav Massif, Kokchetav Oblast', Kazakhstan. Scale: Specimen Size 6x6x6 mm.
© Sergey Vasiliev / Systematic Mineralogy

Kokchetavite Crystallography

Axial Ratios:

a:c = 1:1.48387

Cell Dimensions:

a = 5.27, c = 7.82, Z = 1; V = 188.09 Den(Calc)= 2.46

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6/mmm(?)

Physical Properties of Kokchetavite

Habit:

Inclusions - Generally found as inclusions in other minerals.

Habit:

Platy - Sheet forms (e.g. micas).

Optical Properties of Kokchetavite

Optical Data:

NCalc= 1.51 - from Gladstone-Dale relationship (KC = 0.2058) where Ncalc=Dcalc*KC+1

Calculated Properties of Kokchetavite

Electron Density:

Bulk Density (Electron Density)=2.44 gm/cc
note: Specific Gravity of Kokchetavite =2.46 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Kokchetavite= 2.85 barns/electron
U=PE_Kokchetavite x r_electron= 6.94 barns/cc.

Radioactivity:

GRapi = 200.97 (Gamma Ray American Petroleum Institute Units)
Concentration of Kokchetavite per GRapi unit = 0.50 (%)

Estimated Radioactivity from Kokchetavite - barely detectable

Kokchetavite Classification

Dana Class:

76.01.08.01 (76)Tectosilicate Al-Si Framework

(76.01)with Al-Si frameworks

(76.01.08)Hexagonal Feldspars (High Pressure)

76.01.08.01 Kokchetavite! KAlSi3O8 P 6/mmm(?) 6/m 2/m 2/m

76.01.08.02 Kumdykolite NaAlSi3O8 P 2nn or Pmnn Ortho

Strunz Class:

09.FA.75 09 - SILICATES (Germanates)

09.F - Tektosilicates without Zeolitic H2O

09.FA -Tektosilicates without additional non-tetrahedral anions, (Al,B):Si = 1:1

09.FA.75 Kokchetavite! KAlSi3O8 P 6/mmm(?) 6/m 2/m 2/m

Other Kokchetavite Information

References:

NAME( AmMin, v90, p 1228) PHYS. PROP.(AmMin, v90, p 1228)

See Also:

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

Kokchetavite

KAlSi3O8
Dana No: 76.01.08.01 Strunz No: 09.FA.75
Locality:

Notes:

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