Kokchetavite

K(AlSi3O8)
IMA status
  • Approved
IMA symbol
Kct
IMA approved
2004
Also known as
  • IMA2004-011
  • Kokchetaviet

Where it forms, where it's found

Geological setting

Ultrahigh-grade granitic and biotite gneiss.

Also found as product of crystallization of a silicate melt in polycrystalline inclusions (nanogranitoids).

Type locality
Lake Kumdikol diamond deposit
  1. Lake Kumdikol (Lake Kumdykol'
  2. Ozero Kumdykol')
  3. Prirechnoye
  4. Zerendi District
  5. Akmola Region
  6. Kazakhstan
15recorded occurrences
Source · OpenStreetMap

Physical

Density
2.45 g/cm³

Crystallography

Crystal system
Hexagonal
Space group
#123
Cell parameters
a = 10.5757(3) Å · c = 15.6404(6) Å
Unit cell volume
1514.94 ų
Z
1
Type-locality form

3-7 micrometer plates and prisms.

Comment

Data from Romanenko et al. (2021). Originally assumed to have P6/mmm, with a = 5.27 and c = 7.82 Å.

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen815.999127.992
45.99%
14SiSiliconSilicon328.08584.255
30.27%
19KPotassiumPotassium139.09839.098
14.05%
13AlAluminiumAluminium126.98226.982
9.69%
Total278.327100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • IMA2004-011
  • Kokchetaviet

In other languages

German
IMA 2004-011 · Kokchetavit
Italian
Kokchetavite

Classification

Strunz
10th ed.

9.FA.75

  • 9SilicatesClass
  • 9.FTektosilicates without zeolitic H2ODivision
  • 9.FATektosilicates without additional non-tetrahedral anionsGroup
  • 9.FA.75KokchetaviteSpecies

Group, growth & confusion

In the same group
9 members
Commonly confused with
6 minerals

Literature, links & citation

Citations
  1. 2004Hwang, Shyh-Lung, Shen, Pouyan, Chu, Hao-Tsu, Yui, Tzen-Fu, Liou, Juhn G., Sobolev, Nikolay V., Zhang, Ru-Yuan, Shatsky, Vladislav S., Zayachkovsky, Anton A. (2004) Kokchetavite: a new potassium-feldspar polymorph from the Kokchetav ultrahigh-pressure terrane. Contributions to Mineralogy and Petrology, 148 (3) 380-389 doi:10.1007/s00410-004-0610-2DOI: 10.1007/s00410-004-0610-2
  2. 2013Hwang, S.L., Yui, T.F., Chu, H.T., Shen, P., Liou, J.G., Sobolev, N.V. (2013) Oriented kokchetavite compound rods in clinopyroxene of Kokchetav ultrahigh-pressure rocks. Journal of Asian Earth Sciences, 63. 56-69 doi:10.1016/j.jseaes.2012.09.003DOI: 10.1016/j.jseaes.2012.09.003
  3. 2014Mikhno, Anastasia O., Schmidt, Ute, Korsakov, Andrey V. (2014) Origin of K-cymrite and kokchetavite in the polyphase mineral inclusions from Kokchetav UHP calc-silicate rocks: evidence from confocal Raman imaging. European Journal of Mineralogy, 25 (5) 807-816 doi:10.1127/0935-1221/2013/0025-2321DOI: 10.1127/0935-1221/2013/0025-2321
  4. 2016Ferrero, Silvio; Ziemann, Martin A.; Angel, Ross J.; O’Brien, Patrick J.; Wunder, Bernd (2016) Kumdykolite, kokchetavite, and cristobalite crystallized in nanogranites from felsic granulites, Orlica-Snieznik Dome (Bohemian Massif): not evidence for ultrahigh-pressure conditions. Contributions to Mineralogy and Petrology, 171 (1). 3 doi:10.1007/s00410-015-1220-xDOI: 10.1007/s00410-015-1220-x
  5. 2018Ferrero, Silvio; Angel, Ross J (2018) Micropetrology: Are Inclusions Grains of Truth? Journal of Petrology. doi:10.1093/petrology/egy075DOI: 10.1093/petrology/egy075
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Kokchetavite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/kokchetavite-27460},
  note      = {Accessed 2026-05-11}
}