Alexkhomyakovite
A valid IMA mineral species
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About Alexkhomyakovite
Alexander P. Khomyakov
Formula:
K6(Ca2Na)(CO3)5Cl · 6H2O
Colour:
Colourless, white or grey
Lustre:
Vitreous, Greasy
Hardness:
3
Specific Gravity:
2.25
Crystal System:
Hexagonal
Name:
Named in honour of Alexander Petrovich Khomyakov (Александр Петрович Хомяков) (2 April 1933, Moscow, Russia – 12 October 2012, Moscow, Russia), mineralogist and Director of the Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements. He described more than 100 new minerals. The minerals khomyakovite and manganokhomyakovite are also named for him.
Type Locality:
This page provides mineralogical data about Alexkhomyakovite.
Unique Identifiers
Mindat ID:
46633
Long-form identifier:
mindat:1:1:46633:6
IMA Classification of Alexkhomyakovite
Approved
IMA Formula:
K6(Ca2Na)(CO3)5Cl·6H2O
Approval year:
2015
First published:
2019
Type description reference:
Pekov, Igor V., Zubkova, Natalia V., Yapaskurt, Vasiliy O., Lykova, Inna S., Chukanov, Nikita V., Belakovskiy, Dmitry I., Britvin, Sergey N., Turchkova, Anna G., Pushcharovsky, Dmitry Y. (2019) Alexkhomyakovite, K6(Ca2Na)(CO3)5Cl · 6H2O, a new mineral from the Khibiny alkaline complex, Kola peninsula, Russia. European Journal of Mineralogy, 31 (1) 135-143 doi:10.1127/ejm/2018/0030-2798
Classification of Alexkhomyakovite
5.DA.
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
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 |
|---|---|---|
| Akmy | 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 Alexkhomyakovite
Vitreous, Greasy
Transparency:
Transparent, Translucent
Colour:
Colourless, white or grey
Hardness:
3 on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
2.25(1) g/cm3 (Measured) 2.196 g/cm3 (Calculated)
Optical Data of Alexkhomyakovite
Type:
Uniaxial (-)
RI values:
nω = 1.543(2) nε = 1.476(2)
Max. Birefringence:
δ = 0.067
Based on recorded range of RI values above.
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Low (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Alexkhomyakovite
Mindat Formula:
K6(Ca2Na)(CO3)5Cl · 6H2O
Element Weights:
Crystallography of Alexkhomyakovite
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P63/mcm
Setting:
P63/mcm
Cell Parameters:
a = 9.2691(2) Å, c = 15.8419(4) Å
Ratio:
a:c = 1 : 1.709
Unit Cell V:
1178.72 ų
Z:
2
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.96 Å | (27) |
| 3.486 Å | (35) |
| 3.011 Å | (100) |
| 2.977 Å | (32) |
| 2.676 Å | (36) |
| 2.626 Å | (42) |
| 2.206 Å | (26) |
| 1.982 Å | (17) |
Reference:
Pekov, Igor V., Zubkova, Natalia V., Yapaskurt, Vasiliy O., Lykova, Inna S., Chukanov, Nikita V., Belakovskiy, Dmitry I., Britvin, Sergey N., Turchkova, Anna G., Pushcharovsky, Dmitry Y. (2019) Alexkhomyakovite, K6(Ca2Na)(CO3)5Cl · 6H2O, a new mineral from the Khibiny alkaline complex, Kola peninsula, Russia. European Journal of Mineralogy, 31 (1) 135-143 doi:10.1127/ejm/2018/0030-2798
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Alexkhomyakovite
General Appearance of Type Material:
Equant grains up to 0.2 mm, veinlets up to 3 cm long and up to 1 mm thick and fine-grained aggregates replacing delhayelite
Place of Conservation of Type Material:
Type material is deposited in the collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia, registration number 4696/1
Geological Setting of Type Material:
peralkaline pegmatite
Reference:
Pekov, Igor V., Zubkova, Natalia V., Yapaskurt, Vasiliy O., Lykova, Inna S., Chukanov, Nikita V., Belakovskiy, Dmitry I., Britvin, Sergey N., Turchkova, Anna G., Pushcharovsky, Dmitry Y. (2019) Alexkhomyakovite, K6(Ca2Na)(CO3)5Cl · 6H2O, a new mineral from the Khibiny alkaline complex, Kola peninsula, Russia. European Journal of Mineralogy, 31 (1) 135-143 doi:10.1127/ejm/2018/0030-2798
Synonyms of Alexkhomyakovite
Other Language Names for Alexkhomyakovite
Dutch:Alexkhomyakoviet
French:Alexkhomyakovite
German:Alexkhomyakovit
Norwegian:Alexkhomyakovitt
Russian:Алексхомяковит
Common Associates
Associations Based on Photo Data:
| 1 photo of Alexkhomyakovite associated with Villiaumite | NaF |
| 1 photo of Alexkhomyakovite associated with Thermonatrite | Na2CO3 · H2O |
| 1 photo of Alexkhomyakovite associated with Natrite | Na2CO3 |
Related Minerals - Strunz-mindat Grouping
| 5.DA. | Amoraite | Ca12Al6(OH)36(CO3)2(SO3) · 15H2O |
| 5.DA.05 | Dypingite | Mg5(CO3)4(OH)2 · 5H2O |
| 5.DA.05 | 'UM1986-10-CO:ClHMgMnZn (also called Mineral F, Dunn, 1995)' | Mg5(Zn,Mn)3(CO3)2(OH,Cl)12 · H2O |
| 5.DA.05 | 'UM1987-01-CO:HMgS' | Mg4(CO3)2(OH)4 · 6H2O ? |
| 5.DA.05 | Giorgiosite | Mg5(CO3)4(OH)2 · 5-6H2O |
| 5.DA.05 | Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
| 5.DA.05 | Widgiemoolthalite | Ni5(CO3)4(OH)2 · 5H2O |
| 5.DA.10 | Artinite | Mg2(CO3)(OH)2 · 3H2O |
| 5.DA.10 | Chlorartinite | Mg2(CO3)(OH)Cl · 2H2O |
| 5.DA.10 | Indigirite | Mg2Al2(CO3)4(OH)2 · 15H2O |
| 5.DA.15 | Zaratite | Ni3(CO3)(OH)4 · 4H2O ? |
| 5.DA.15 | Otwayite | Ni2(CO3)(OH)2 · H2O |
| 5.DA.20 | Kambaldaite | NaNi4(CO3)3(OH)3 · 3H2O |
| 5.DA.25 | Callaghanite | Cu2Mg2(CO3)(OH)6 · 2H2O |
| 5.DA.30 | Claraite | (Cu,Zn)15(CO3)4(AsO4)2(SO4)(OH)14 · 7H2O |
| 5.DA.35 | Hydroscarbroite | Al14(CO3)3(OH)36 · nH2O |
| 5.DA.35 | Scarbroite | Al5(CO3)(OH)13 · 5H2O |
| 5.DA.40 | Karchevskyite | Mg18Al9(OH)54Sr2(CO3)9(H2O)6(H3O)5 |
| 5.DA.40 | 'UM1987-05-OH:AlCMg' | Mg4Al2(OH)12(CO3,SO4) · 3H2O |
| 5.DA.40 | Quintinite | Mg4Al2(OH)12(CO3) · 3H2O |
| 5.DA.40 | Charmarite | Mn2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.40 | Caresite | Fe2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Hydrotalcite-2H' | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | 'Stichtite-2H' | Mg6(Cr,Al)2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | Brugnatellite | Mg6Fe3+(CO3)(OH)13 · 4H2O |
| 5.DA.45 | Zaccagnaite | Zn4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Pyroaurite-2H' | Mg6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.45 | Liudongshengite | Zn4Cr2(OH)12(CO3) · 3H2O |
| 5.DA.45 | Chlormagaluminite | Mg4Al2(OH)12Cl2 · 3H2O |
| 5.DA.50 | Pyroaurite | Mg6Fe3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Takovite | Ni6Al2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Reevesite | Ni6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.50 | Kaznakhtite | Ni6Co3+2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Comblainite | Ni4Co2(OH)12[CO3] · 3H2O |
| 5.DA.50 | Marioantofilliite | [Cu4Al2(OH)12](CO3) · 3H2O |
| 5.DA.50 | Hydrotalcite | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Stichtite | Mg6Cr3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Desautelsite | Mg6Mn3+2(OH)16[CO3] · 4H2O |
| 5.DA.55 | Coalingite | Mg10Fe3+2(OH)24[CO3] · 2H2O |
| 5.DA.55 | Akopovaite | Al4Li2(OH)12(CO3)(H2O)3 |
| 5.DA.60 | Šlikite | Zn2Mg(CO3)2(OH)2 · 4H2O |
| 5.DA.65 | Marklite | Cu5(CO3)2(OH)6 · 6H2O |
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) | 30.0246% | 9,308 | 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 Alexkhomyakovite
mindat.org URL:
https://www.mindat.org/min-46633.html
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References for Alexkhomyakovite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2015) New minerals and nomenclature modifications approved in 2015, CNMNC Newsletter No 25. Mineralogical Magazine, 79 (3) 529-535 doi:10.1180/minmag.2015.079.3.02
Pekov, Igor V., Zubkova, Natalia V., Yapaskurt, Vasiliy O., Lykova, Inna S., Chukanov, Nikita V., Belakovskiy, Dmitry I., Britvin, Sergey N., Turchkova, Anna G., Pushcharovsky, Dmitry Y. (2019) Alexkhomyakovite, K6(Ca2Na)(CO3)5Cl · 6H2O, a new mineral from the Khibiny alkaline complex, Kola peninsula, Russia. European Journal of Mineralogy, 31 (1) 135-143 doi:10.1127/ejm/2018/0030-2798
Localities for Alexkhomyakovite
Showing 1 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.
Russia (TL) | |
| Hålenius et al. (2015) +1 other reference |
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Koashva Open Pit, Koashva Mt, Murmansk Oblast, Russia