Kokchetavite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
Formula:
K(AlSi3O8)
Specific Gravity:
2.45 (Calculated)
Crystal System:
Hexagonal
Member of:
Name:
Named after the Kokchetav Massif, Kazakhstan that includes the type locality.
Type Locality:
Polymorph of:
Isostructural with:
Metastable polymorph. Found within multiphase inclusions in garnet, clinopyroxene and zircon. Formed likely either due to (1) a precipitate of infiltrated K-rich melt during cooling and/or decompression, 2) product of rapid crystallization, triggered by supersaturation and rapid cooling, of a melt trapped in a mineral phase; 3) dehydration of the HP phase 'K-cymrite'.
The K4-analogue of pfaffenbergite; the K4(Al4Si12)-analogue of wodegongjieite. The analogy towards pfaffenbergite may be imaged after multiplication of the kokchetavite formula by 4 → K4(Al4Si12)O32.
The K4-analogue of pfaffenbergite; the K4(Al4Si12)-analogue of wodegongjieite. The analogy towards pfaffenbergite may be imaged after multiplication of the kokchetavite formula by 4 → K4(Al4Si12)O32.
Unique Identifiers
Mindat ID:
27460
Long-form identifier:
mindat:1:1:27460:1
IMA Classification of Kokchetavite
Classification of Kokchetavite
9.FA.75
9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H2O
A : Tektosilicates without additional non-tetrahedral anions
9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H2O
A : Tektosilicates without additional non-tetrahedral anions
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Kct | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Kokchetavite
Density:
2.45 g/cm3 (Calculated)
Chemistry of Kokchetavite
Mindat Formula:
K(AlSi3O8)
Element Weights:
Elements listed:
Crystallography of Kokchetavite
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P6/mcc
Cell Parameters:
a = 10.5757(3) Å, c = 15.6404(6) Å
Ratio:
a:c = 1 : 1.479
Unit Cell V:
1514.94 ų
Z:
1
Comment:
Data from Romanenko et al. (2021). Originally assumed to have P6/mmm, with a = 5.27 and c = 7.82 Å.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.82 Å | () |
| 4.56 Å | () |
| 3.93 Å | () |
| 2.98 Å | () |
| 2.63 Å | () |
| 2.51 Å | () |
| 2.26 Å | () |
| 1.80 Å | () |
| 1.72 Å | () |
| 1.68 Å | () |
Comments:
No PXRD in type description. The data above are lines from the SAED pattern. Data are from the type description. No intensities are given.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 39 : High-? metamorphism (blueschist, eclogite, ultrahigh ? facies) |
Geological Setting:
Also found as product of crystallization of a silicate melt in polycrystalline inclusions (nanogranitoids).
Type Occurrence of Kokchetavite
General Appearance of Type Material:
3-7 micrometer plates and prisms.
Place of Conservation of Type Material:
National Museum of Natural Science, Taichung, Taiwan.
Geological Setting of Type Material:
Ultrahigh-grade granitic and biotite gneiss.
Associated Minerals at Type Locality:
Synonyms of Kokchetavite
Other Language Names for Kokchetavite
Relationship of Kokchetavite to other Species
Member of:
Other Members of Feldspar Group:
| Alkali Feldspar | A subgroup of the Feldspar Group, poor in calcium, and mostly rich in potassium. | |
| Buddingtonite | (NH4)(AlSi3O8) | Mon. 2 : P21 |
| Celsian | Ba(Al2Si2O8) | Mon. 2/m |
| Filatovite | K(Al,Zn)2(As,Si)2O8 | Mon. 2/m |
| Hexacelsian | BaAl2Si2O8 | Hex. 6/mmm(6/m2/m2/m) : P63/mcm |
| Kumdykolite | Na(AlSi3O8) | Orth. mmm(2/m2/m2/m) : Pnnm |
| Paracelsian | Ba(Al2Si2O8) | Mon. 2/m : P21/b |
| Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 | |
| Reedmergnerite | NaBSi3O8 | Tric. 1 : P1 |
| Slawsonite | Sr(Al2Si2O8) | Mon. 2/m : P21/b |
| Svyatoslavite | Ca(Al2Si2O8) | Mon. 2 : P21 |
| 'Unnamed (New Ordered Member of the Alkali Feldspar Series)' | KNa(Si6Al2)O16 | Mon. m |
Related Minerals - Strunz-mindat Grouping
| 9.FA. | Bonaccorsiite | KK2Na3(Al6Si36)O84 |
| 9.FA. | Hexacelsian | BaAl2Si2O8 |
| 9.FA. | Wodegongjieite | KCa3(Al7Si9)O32 |
| 9.FA.05 | Panunzite | (K,Na)AlSiO4 |
| 9.FA.05 | Yoshiokaite | (Ca,Na)[Al(Al,Si)O4] |
| 9.FA.05 | Nepheline | Na3K(Al4Si4O16) |
| 9.FA.05 | Trinepheline | NaAlSiO4 |
| 9.FA.05 | Davidsmithite | (Ca,◻)2Na6Al8Si8O32 |
| 9.FA.05 | Kaliophilite | KAlSiO4 |
| 9.FA.05 | Kalsilite | KAlSiO4 |
| 9.FA.05 | 'Carnegieite' | NaAlSiO4 |
| 9.FA.05 | Megakalsilite | KAlSiO4 |
| 9.FA.05 | Trikalsilite | K2NaAl3(SiO4)3 |
| 9.FA.10 | Malinkoite | NaBSiO4 |
| 9.FA.15 | Virgilite | LiAlSi2O6 |
| 9.FA.25 | Lisitsynite | KBSi2O6 |
| 9.FA.30 | Ferrisanidine | K[Fe3+Si3O8] |
| 9.FA.30 | Buddingtonite | (NH4)(AlSi3O8) |
| 9.FA.30 | Rubicline | Rb(AlSi3O8) |
| 9.FA.30 | 'Monalbite' | NaAlSi3O8 |
| 9.FA.30 | Microcline | K(AlSi3O8) |
| 9.FA.30 va | 'Germanate-celsian' | BaAl2Ge2O8 |
| 9.FA.30 | Celsian | Ba(Al2Si2O8) |
| 9.FA.30 | Sanidine | K(AlSi3O8) |
| 9.FA.30 | Orthoclase | K(AlSi3O8) |
| 9.FA.35 | Reedmergnerite | NaBSi3O8 |
| 9.FA.35 | Albite | Na(AlSi3O8) |
| 9.FA.35 | Anorthite | Ca(Al2Si2O8) |
| 9.FA.40 | Paracelsian | Ba(Al2Si2O8) |
| 9.FA.45 | Svyatoslavite | Ca(Al2Si2O8) |
| 9.FA.45 | Kumdykolite | Na(AlSi3O8) |
| 9.FA.50 | Slawsonite | Sr(Al2Si2O8) |
| 9.FA.55 | Lisetite | CaNa2Al4Si4O16 |
| 9.FA.60 | Stronalsite | Na2SrAl4Si4O16 |
| 9.FA.60 | Banalsite | Na2BaAl4Si4O16 |
| 9.FA.65 | Maleevite | BaB2Si2O8 |
| 9.FA.65 | Pekovite | SrB2Si2O8 |
| 9.FA.65 | Danburite | CaB2Si2O8 |
| 9.FA.70 | Liebermannite | KAlSi3O8 |
| 9.FA.70 | Lingunite | NaAlSi3O8 |
| 9.FA.70 | Stöfflerite | CaAl2Si2O8 |
| 9.FA.75 | Pfaffenbergite | KNa3(Al4Si12)O32 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 14.0474% | 4,355 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Kokchetavite
mindat.org URL:
https://www.mindat.org/min-27460.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Kokchetavite
Reference List:
Hwang, 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/s00410-004-0610-2
Hwang, 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.2012.09.003
Mikhno, 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:10.1127/0935-1221/2013/0025-2321
Ferrero, 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-x
Ferrero, Silvio; Angel, Ross J (2018) Micropetrology: Are Inclusions Grains of Truth? Journal of Petrology. doi:10.1093/petrology/egy075
Borghini, Alessia; Ferrero, Silvio; Wunder, Bernd; Laurent, Oscar; O’Brien, Patrick J.; Ziemann, Martin A. (2018) Granitoid melt inclusions in orogenic peridotite and the origin of garnet clinopyroxenite. Geology, 46 (11). 1007-1010 doi:10.1130/g45316.1
Carvalho, Bruna B., Bartoli, Omar, Ferri, Fabio, Cesare, Bernardo, Ferrero, Silvio, Remusat, Laurent, Capizzi, Luca S., Poli, Stefano (2019) Anatexis and fluid regime of the deep continental crust: New clues from melt and fluid inclusions in metapelitic migmatites from Ivrea Zone (
NW
Italy) Journal of Metamorphic Geology, 37 (7) 951-975 doi:10.1111/jmg.12463
Romanenko, Alexandr V., Rashchenko, Sergey V., Sokol, Alexander G., Korsakov, Andrey V., Seryotkin, Yurii V., Glazyrin, Konstantin V., Musiyachenko, Kira (2021) Crystal structures of K-cymrite and kokchetavite from single-crystal X-ray diffraction. American Mineralogist, 106 (3) 404-409 doi:10.2138/am-2020-7407
Ferrero, S., Wannhoff, I., Laurent, O., Yakymchuk, C., Darling, R., Wunder, B., Borghini, A., O'Brien, P.J. (2021) Embryos of TTGs in Gore Mountain garnet megacrysts from water-fluxed melting of the lower crust. Earth and Planetary Science Letters, 569. 117058pp. doi:10.1016/j.epsl.2021.117058
Gianola, Omar, Bartoli, Omar, Ferri, Fabio, Galli, Andrea, Ferrero, Silvio, Capizzi, Luca S., Liebske, Christian, Remusat, Laurent, Poli, Stefano, Cesare, Bernardo (2021) Anatectic melt inclusions in ultra high temperature granulites. Journal of Metamorphic Geology, 39 (3) 321-342 doi:10.1111/jmg.12567
Nicoli, Gautier, Gresky, Kerstin, Ferrero, Silvio (2022) Mesoarchean melt and fluid inclusions in garnet from the Kangerlussuaq basement, Southeast Greenland. Mineralogia, 53 (1) 1-9 doi:10.2478/mipo-2022-0001
Fei, Chenhui; Liu, Jingbo (2022) Whewellite-Bearing Fluid Inclusions in Zircons From a Stromatic Migmatite in the Chinese Sulu Ultrahigh-Pressure Metamorphic Belt. Journal of Petrology, 63 (8). egac071 doi:10.1093/petrology/egac071
Stähle, Volker, Chanmuang N., Chutimun, Schwarz, Winfried H., Trieloff, Mario, Varychev, Alexander (2022) Newly detected shock-induced high-pressure phases formed in amphibolite clasts of the suevite breccia (Ries impact crater, Germany): Liebermannite, kokchetavite, and other ultrahigh-pressure phases. Contributions to Mineralogy and Petrology, 177 (8) doi:10.1007/s00410-022-01936-3
Korsakov, Andrey V., Romanenko, Alexandr V., Sokol, Alexander G., Musiyachenko, Kira A. (2023) Raman spectroscopic study of the transformation of nitrogen‐bearing K‐cymrite during heating experiments: Origin of kokchetavite in high‐pressure metamorphic rocks. Journal of Raman Spectroscopy, 54 (11) 1183-1190 doi:10.1002/jrs.6541
Liu, Zhao, Carvalho, Bruna B, Li, Wancai, Tong, Laixi, Bartoli, Omar, Chen, Longyao, Yan, Qinghe, Wu, Haobo (2023) Into the High to Ultrahigh Temperature Melting of Earth’s Crust: Investigation of Melt and Fluid Inclusions within Mg-Rich Metapelitic Granulites from the Mather Peninsula, East Antarctica. Journal of Petrology, 64 (7) Oxford University Press (OUP) doi:10.1093/petrology/egad051
Romanenko, Alexandr V., Rashchenko, Sergey V., Korsakov, Andrey V., Sokol, Alexander G., Kokh, Konstantin A. (2024) Compressibility and pressure-induced structural evolution of kokchetavite, hexagonal polymorph of KAlSi3O8, by single-crystal X-ray diffraction. American Mineralogist, 109 (7) 1284-1291 doi:10.2138/am-2023-9120
Localities for Kokchetavite
Showing 19 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Antarctica | |
| Liu et al. (2023) |
| Ferrero et al. (2018) |
Austria | |
| Sorger (2019) |
China | |
| Masami Kanzaki et al. (2011) |
| Fei et al. (2022) |
Croatia | |
| Schneider et al. (2022) |
Czech Republic | |
| Wannhoff et al. (2022) |
Germany | |
| Stähle et al. (2022) | |
| Wannhoff et al. (2022) |
| Thomas et al. (2022) |
| Borghini et al. (2023) +2 other references | |
Greenland | |
| Nicoli et al. (2022) |
Italy | |
| Carvalho et al. (2019) |
Kazakhstan | |
| Hwang et al. (2013) |
| Hwang et al. (2004) |
Papua New Guinea | |
| Baldwin et al. (2021) |
Poland | |
| Ferrero et al. (2016) |
Ukraine | |
| SEMONOVA (2025) |
USA | |
| Ferrero et al. (2023) |
Quick NavTopUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
