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Kumtyubeite

A valid IMA mineral species
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About KumtyubeiteHide

Formula:
Ca5(SiO4)2F2
Colour:
Light pink
Lustre:
Vitreous
Hardness:
5 - 6
Specific Gravity:
2.866 (Calculated)
Crystal System:
Monoclinic
Name:
Named in 2009 by Irina О. Galuskina, Biljana Lazic, Thomas Armbruster, Evgeny V. Galuskin, Viktor M. Gazeev, Aleksander E. Zadov, Nikolai N. Pertsev, Lidia Jeżak, Roman Wrzalik, and Anatoly G. Gurbanov for Kum-Tyube, a mountain plateau where the mineral was found.
Kumtyubeite is the calcium analogue of chondrodite and the fluorine analogue of reinhardbraunsite. It is possibly identical with the anthropogenic "kutyukhinite".

Galuskina et al. (2009) compared the F/(OH) ratio for about 150 compositions from electron microprobe analyses of reinhardbraunsite-kumtyubeite from Lakargi Mountain. They found a solid-solution series between the two rare minerals and find the ratios from F/(F + OH) ≈ 0.15 (maximally hydrated reinhardbraunsite) to F/(F + OH) ≈ 0.75 (maximally fluorinated kumtyubeite).

Galuskin et al. (2009) suggest that a skarn has been formed at 750-1000°C / 30 MPa in the contact between sedimentary carbonate rocks and magma in a subvolcanic magma chamber at a depth of 1.5 km, and then kumtyubeite was formed by decarbonization during magma ascent and volcanic eruption (high CaO activity at sharply dropping CO2 fugacity and fluid pressure).


Unique IdentifiersHide

Mindat ID:
39209
Long-form identifier:
mindat:1:1:39209:5

IMA Classification of KumtyubeiteHide

Classification of KumtyubeiteHide

9.AF.45

9 : SILICATES (Germanates)
A : Nesosilicates
F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination
52.3.3.4

52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
3 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] coordination only

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference
KtyIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of KumtyubeiteHide

Vitreous
Transparency:
Transparent, Translucent
Colour:
Light pink
Streak:
White
Hardness:
5 - 6 on Mohs scale
Hardness:
VHN50=280 - 320 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Distinct/Good
distinct on (001)
Density:
2.866 g/cm3 (Calculated)

Optical Data of KumtyubeiteHide

Type:
Biaxial (-)
RI values:
nα = 1.594(2) nβ = 1.605(2) nγ = 1.608(2)
2V:
Measured: 40° to 55°, Calculated: 54.8°
Birefringence:
0.014
Max. Birefringence:
δ = 0.014
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.

Surface Relief:
Moderate
Optical Extinction:
X^c = 15°, Z = b.

Chemistry of KumtyubeiteHide

Mindat Formula:
Ca5(SiO4)2F2
Element Weights:
Element% weight
Ca47.424 %
O30.291 %
Si13.293 %
F8.992 %

Calculated from ideal end-member formula.

Crystallography of KumtyubeiteHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 11.4340(19) Å, b = 5.0575(9) Å, c = 8.8657(16) Å
β = 108.860(12)°
Ratio:
a:b:c = 2.261 : 1 : 1.753
Unit Cell V:
485.16 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Granular patches in skarn
Twinning:
polysynthetic, twins on (001)

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
8.3830 Å(1)
5.4202 Å(30)
4.5824 Å(1)
4.3297 Å(3)
4.1915 Å(3)
4.00006 Å(4)
3.8031 Å(13)
3.3273 Å(21
3.2269 Å(4)
3.1374 Å(3)
3.0344 Å(37)
2.9399 Å(17)
2.9018 Å(16)
2.8932 Å(13)
2.8635 Å(3)
2.7943 Å(2)
2.7737 Å(25)
2.7101 Å(12)
2.5713 Å(20)
2.5452 Å(12)
2.5282 Å(2)
2.5112 Å(17)
2.4917 Å(10)
2.4621 Å(2)
2.3640 Å(2)
2.3168 Å(2)
2.2530 Å(2)
2.1369 Å(3)
2.0511 Å(2)
2.0126 Å(4)
1.9926 Å(3)
1.9360 Å(2)
1.9128 Å(2)
1.9040 Å(100)
1.8952 Å(37)
1.8748 Å(2)
1.8209 Å(4)
1.8145 Å(2)
1.8063 Å(14)
1.8027 Å(23)
1.7267 Å(6)
1.7216 Å(6)
1.6915 Å(4)
1.6766 Å(9)
1.6655 Å(1)
1.6587 Å(28)
1.6492 Å(3)
1.6183 Å(2)
1.5748 Å(2)
1.5551 Å(6)
1.5403 Å(8)
1.5274 Å(2)
1.5221 Å(1)
1.5026 Å(2)
1.4925 Å(4)
Comments:
American Mineralogist, 94, 1361–1370.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 3a: Earth’s earliest Hadean crust>4.50
9 : Lava/xenolith minerals (hornfels, sanidinite facies)
Stage 7: Great Oxidation Event<2.4
45b : [Other oxidized fumarolic minerals]
Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere<0.6
51 : Pyrometamorphic minerals (see also #54 and #56)<0.36
Stage 10b: Anthropogenic minerals<10 Ka
54 : Coal and other mine fire minerals (see also #51 and #56)
Geological Setting:
Skarns, burned coal dumps.

Type Occurrence of KumtyubeiteHide

General Appearance of Type Material:
Pale pink grains to 0.25 mm in 1 cm granular aggregates.
Place of Conservation of Type Material:
Museum of Natural History, Bern, specimen number NMBE 39572 and in the collection of the Fersman Mineralogical Museum, Moscow, specimen number 3732/1.
Geological Setting of Type Material:
In contact-metasomatic rocks formed by interaction of carbonate xenoliths with subvolcanic magma and volcanites. The mineral occurs in spurrite-rondorfite-ellestadite zones of skarn.
Associated Minerals at Type Locality:

Synonyms of KumtyubeiteHide

Other Language Names for KumtyubeiteHide

Relationship of Kumtyubeite to other SpeciesHide

Other Members of Chegemite Subgroup:
ChegemiteCa7(SiO4)3(OH)2Orth. mmm (2/m 2/m 2/m)
EdgrewiteCa9(SiO4)4F2 Mon. 2/m : P21/b
FluorchegemiteCa7(SiO4)3F2 Orth. mmm (2/m 2/m 2/m)
HydroxyledgrewiteCa9(SiO4)4(OH)2 Mon. 2/m : P21/b
ReinhardbraunsiteCa5(SiO4)2(OH,F)2Mon. 2/m : P21/b

Related Minerals - Strunz-mindat GroupingHide

9.AF.ChegemiteCa7(SiO4)3(OH)2Orth. mmm (2/m 2/m 2/m)
9.AF.Jingwenite-(Y)YAlV4+(SiO4)O2(OH)2Mon. 2/m
9.AF.BarwooditeMn2+6Nb5+(SiO4)2O3(OH)3Trig. 3 : P3
9.AF.05SillimaniteAl2(SiO4)OOrth. mmm (2/m 2/m 2/m)
9.AF.05XenoliteAl10Si8O31
9.AF.10KanonaiteMn3+Al(SiO4)OOrth. mmm (2/m 2/m 2/m) : Pnnm
9.AF.10AndalusiteAl2(SiO4)OOrth. mmm (2/m 2/m 2/m) : Pnnm
9.AF.15KyaniteAl2(SiO4)OTric. 1 : P1
9.AF.20KrieseliteAl2(GeO4)F2Orth. mmm (2/m 2/m 2/m) : Pnma
9.AF.20MulliteAl4+2xSi2-2xO10-xOrth. mmm (2/m 2/m 2/m) : Pbam
9.AF.23BoromulliteAl9BSi2O19Orth. mm2 : Cmc21
9.AF.25YoderiteMg(Al,Fe3+)3(SiO4)2O(OH)Mon. 2/m : P21/m
9.AF.30ZincostauroliteZn2Al9Si4O23(OH)Mon. 2/m : B2/m
9.AF.30StauroliteFe2+2Al9Si4O23(OH)Mon. 2/m : B2/m
9.AF.30MagnesiostauroliteMg(Mg,Li)3(Al,Mg)18Si8O44(OH)4Mon. 2/m : B2/m
9.AF.35TopazAl2(SiO4)(F,OH)2Orth. mmm (2/m 2/m 2/m)
9.AF.40NorbergiteMg3(SiO4)F2Orth. mmm (2/m 2/m 2/m)
9.AF.45ChondroditeMg5(SiO4)2F2Mon. 2/m : P21/b
9.AF.45ReinhardbraunsiteCa5(SiO4)2(OH,F)2Mon. 2/m : P21/b
9.AF.45HydroxylchondroditeMg5(SiO4)2(OH)2Mon. 2/m : P21/b
9.AF.45AlleghanyiteMn2+5(SiO4)2(OH)2Mon. 2/m : P21/b
9.AF.50Unnamed (Ca-analogue of Humite)Ca7(SiO4)4F2Orth. mmm (2/m 2/m 2/m)
9.AF.50HumiteMg7(SiO4)3F2Orth. mmm (2/m 2/m 2/m) : Pnma
9.AF.50Manganhumite(Mn2+,Mg)7(SiO4)3(OH)2Orth. mmm (2/m 2/m 2/m)
9.AF.50Unnamed (OH-analogue of humite)Mg7(SiO4)3(OH)2Orth.
9.AF.50FluorchegemiteCa7(SiO4)3F2 Orth. mmm (2/m 2/m 2/m)
9.AF.55HydroxylclinohumiteMg9(SiO4)4(OH)2Mon. 2/m : P21/b
9.AF.55ClinohumiteMg9(SiO4)4F2Mon. 2/m : P21/b
9.AF.55SonoliteMn2+9(SiO4)4(OH)2Mon. 2/m : P21/b
9.AF.60LeucophoeniciteMn2+7(SiO4)3(OH)2Mon. 2/m : P21/b
9.AF.65RibbeiteMn2+5(SiO4)2(OH)2Orth. mmm (2/m 2/m 2/m)
9.AF.70JerrygibbsiteMn2+9(SiO4)4(OH)2Orth. mmm (2/m 2/m 2/m) : Pbcn
9.AF.75FranciscaniteMn2+6(V5+,◻)2(SiO4)2(O,OH)6Trig. 3 : P3
9.AF.75ScorticoiteMn6(Sb,◻)Σ2(SiO4)2O3(OH)3Trig. 3 : P3
9.AF.75WeliniteMn2+6(W6+,Mg)2(SiO4)2(O,OH)6Trig. 3 : P3
9.AF.75ÖrebroiteMn2+3(Sb5+,Fe3+)(SiO4)(O,OH)3Trig. 3 : P3
9.AF.80EllenbergeriteMg6(Mg,Ti,Zr,◻)2(Al,Mg)6Si8O28(OH)10Hex. 6 : P63
9.AF.85MagnesiochloritoidMgAl2O(SiO4)(OH)2Mon. 2/m : B2/b
9.AF.85OttréliteMn2+Al2O(SiO4)(OH)2Mon.
9.AF.85ChloritoidFe2+Al2O(SiO4)(OH)2Mon. 2/m : B2/b
9.AF.90OlmiiteCaMn2+[SiO3(OH)](OH)Orth. mmm (2/m 2/m 2/m) : Pbca
9.AF.90PoldervaartiteCaCa[SiO3(OH)](OH)Orth. mmm (2/m 2/m 2/m) : Pbca
9.AF.95Pilawite-(Y)Ca2Y2Al4(SiO4)4O2(OH)2Mon. 2/m : P21/b

Other InformationHide

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 KumtyubeiteHide

References for KumtyubeiteHide

Localities for KumtyubeiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Czech Republic
 
  • South Moravian Region
    • Brno-Country District
      • Oslavany
Hršelová et al. (2013)
Georgia
 
  • South Ossetia
    • Greater Caucasus Mountain Range
      • Kel’ volcanic area
        • Shadil-Khokh volcano
Galuskina et al. (2015)
Germany
 
  • Rhineland-Palatinate
    • Mayen-Koblenz
      • Vordereifel
Blaß et al. (2015)
Jordan
 
  • Amman Governorate
    • Transjordan Plateau
      • Daba-Siwaqa complex
        • Hashem region
          • Lisdan-Siwaga Fault
Fleurance et al. (2013)
Russia (TL)
 
  • Kabardino-Balkaria
    • Chegemsky District
      • Upper Chegem volcanic caldera (Verkhnechegemskaya caldera)
        • Lakargi Mountain
Galuskina et al. (2009)
Ukraine
 
  • Donetsk Oblast
    • Gorlovka
      • Kalinin coal mine
Шарыгин (2015)
 
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