Melkovite
A valid IMA mineral species
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About Melkovite
Formula:
[Ca2(H2O)15Ca(H2O)6][Mo8P2Fe3+3O36(OH)]
Colour:
Brownish yellow; lemon yellow
Lustre:
Waxy, Dull
Hardness:
3
Specific Gravity:
2.969 - 2.973
Crystal System:
Monoclinic
Member of:
Name:
First described from a U-Mo deposit, Shunak Mts, Kazakhstan by Yegorov et al. (1969). Named in honour of Professor Vyacheslav Gavrilovich Melkov (Вячеслав Гаврилович Мелков)(1911–1991), Russian mineralogist specializing in uranium minerals, of the All-Union Research Institute of Mineral Resources, Moscow, Russia.
The mineral vyacheslavite is also named in his honor.
The mineral vyacheslavite is also named in his honor.
Unique Identifiers
Mindat ID:
2637
Long-form identifier:
mindat:1:1:2637:2
GUID
(UUID V4):
(UUID V4):
85801c54-c5c2-42ee-9a73-6a422abe7de5
IMA Classification of Melkovite
Classification of Melkovite
8.DM.15
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
M : With large and medium-sized cations, (OH, etc.):RO4 > 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
M : With large and medium-sized cations, (OH, etc.):RO4 > 2:1
49.4.3.1
49 : HYDRATED MOLYBDATES AND TUNGSTATES
4 : Compound Molybdates and Tungstates
49 : HYDRATED MOLYBDATES AND TUNGSTATES
4 : Compound Molybdates and Tungstates
22.5.11
22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate
22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate
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 |
---|---|---|
Mko | 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 Melkovite
Waxy, Dull
Transparency:
Transparent
Colour:
Brownish yellow; lemon yellow
Hardness:
3 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
One perfect cleavage
One perfect cleavage
Density:
2.969 - 2.973 g/cm3 (Measured) 2.851 g/cm3 (Calculated)
Optical Data of Melkovite
Type:
Biaxial
Dispersion:
strong
Optical Extinction:
Extinction wavy to nearly parallel ⊥ to the cleavage.
Pleochroism:
Weak
Comments:
Colourless to light green.
Comments:
n(average) = 1.838.
Chemistry of Melkovite
Mindat Formula:
[Ca2(H2O)15Ca(H2O)6][Mo8P2Fe3+3O36(OH)]
Crystallography of Melkovite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 18.81(9) Å, b = 10.99(10) Å, c = 15.11(9) Å
β = 129.6(2)°
β = 129.6(2)°
Ratio:
a:b:c = 1.712 : 1 : 1.375
Unit Cell V:
2407 ų
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
8.42 Å | (70) |
3.537 Å | (80) |
3.036 Å | (70) |
2.916 Å | (90) |
2.415 Å | (50) |
1.992 Å | (60) |
1.789 Å | (70) |
Comments:
Shunak Mountains, Kazakhstan. The data are from the type description. The maximum value is 90/100 because intensities were in relation to data for heated material.
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47c : [Carbonates, phosphates, borates, nitrates] |
Type Occurrence of Melkovite
General Appearance of Type Material:
Finely crystalline powdery films and veinlets consisting of platy crystals generally 0.001-0.002 mm in diameter.
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, 72716.
National Museum of Natural History, Washington, D.C., USA, 160237.
National Museum of Natural History, Washington, D.C., USA, 160237.
Geological Setting of Type Material:
Oxidation zone of a molybdenite-fluorite deposit.
Associated Minerals at Type Locality:
Synonyms of Melkovite
Other Language Names for Melkovite
Relationship of Melkovite to other Species
Member of:
Other Members of this group:
Mendozavilite-KCa | [K2(H2O)15Ca(H2O)6][Mo8P2Fe3+3O34(OH)3] | Mon. 2/m : B2/m |
Mendozavilite-NaCu | [Na2(H2O)15Cu(H2O)6][Mo8P2Fe3+3O34(OH)3] | Mon. 2/m : B2/m |
Mendozavilite-NaFe | [Na2(H2O)15Fe3+(H2O)6][Mo8P2Fe3+3O35(OH)2] | Mon. 2/m : B2/m |
Common Associates
Associated Minerals Based on Photo Data:
2 photos of Melkovite associated with Jarosite | KFe3+3(SO4)2(OH)6 |
2 photos of Melkovite associated with Iriginite | (UO2)Mo2O7 · 3H2O |
2 photos of Melkovite associated with Ferrimolybdite | Fe2(MoO4)3 · nH2O |
2 photos of Melkovite associated with Fluorite | CaF2 |
2 photos of Melkovite associated with Unnamed (Hydrous Zr Molybdate) | Zr-Mo-O-OH |
Related Minerals - Strunz-mindat Grouping
8.DM. | Betpakdalite-CaMg | [Ca2(H2O)17Mg(H2O)6][Mo8As2Fe3+3O36(OH)] |
8.DM. | Betpakdalite-FeFe | [Fe3+2 (H2O)15(OH)2Fe3+(H2O)6][Mo8As2Fe3+3O37] |
8.DM. | Penriceite | [Mg(H2O)6][Na(H2O)2Al3(PO4)2F6] · H2O |
8.DM. | Elliottite | NaMgAl3(PO4)2F6 · 9H2O |
8.DM. | Sarrochite | [Ca4(H2O)38][Mo8P2Fe3+3O37(OH)] |
8.DM. | Tomsquarryite | NaMgAl3(PO4)2(OH)6 · 8H2O |
8.DM.05 | Morinite | NaCa2Al2(PO4)2(OH)F4 · 2H2O |
8.DM.05 | Esperanzaite | NaCa2Al2(AsO4)2(OH)F4 · 2H2O |
8.DM.10 | Tyrolite | Ca2Cu9(AsO4)4(CO3)(OH)8 · 11H2O |
8.DM.10 | Tangdanite | Ca2Cu9(AsO4)4(SO4)0.5(OH)9 · 9H2O |
8.DM.15 | Betpakdalite-CaCa | [Ca2(H2O)17Ca(H2O)6][Mo6+8As5+2Fe3+3O36(OH)] |
8.DM.15 | Betpakdalite-NaCa | [Na2(H2O)17Ca(H2O)6][Mo6+8As5+2Fe3+3O34(OH)3] |
8.DM.20 | Phosphovanadylite-Ba | Ba[V4+4P2O8(OH)8] · 12H2O |
8.DM.20 | Phosphovanadylite-Ca | Ca[V4+4P2O12(OH)4] · 12H2O |
8.DM.25 | Yukonite | Ca3Fe3+(AsO4)2(OH)3 · 5H2O |
8.DM.30 | Uduminelite | Ca3Al8(PO4)2O12 · 2H2O |
8.DM.35 | Aldermanite | [Mg(H2O)6][Na(H2O)2Al3(PO4)2(OH,F)6] · H2O |
8.DM.35 | Azovskite | Fe3+3(PO4)(OH)6 or near |
8.DM.35 | Delvauxite | CaFe4(PO4,SO4)2(OH)8 · 4-6H2O not confirmed |
8.DM.40 | Santafeite | (Na,Ca,Sr)12(Mn2+,Fe3+,Al,Mg)8Mn4+8(VO4)16(OH,O)20 · 8H2O |
8.DM.55 | Tapiaite | Ca5Al2(AsO4)4(OH)4 · 12H2O |
8.DM.60 | Alcantarillaite | [Fe3+0.5(H2O)4][CaAs3+2(Fe3+2.5W6+0.5)(AsO4)2O7] |
Fluorescence of Melkovite
None
Other Information
Notes:
Slowly soluble in concentrated HCl
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 Melkovite
mindat.org URL:
https://www.mindat.org/min-2637.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
References for Melkovite
Reference List:
Kampf, A. R., Mills, S. J., Rumsey, M. S., Dini, M., Birch, W. D., Spratt, J., Pluth, J. J., Steele, I. M., Jenkins, R. A., Pinch, W. W. (2012) The heteropolymolybdate family: structural relations, nomenclature scheme and new species. Mineralogical Magazine, 76 (5) 1175-1207 doi:10.1180/minmag.2012.076.5.09
Localities for Melkovite
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).
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.
All localities listed without proper references should be considered as questionable.
Quick NavTopAbout MelkoviteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
U-Mo occurrence, Shunak Mountains, Mointy Railway Station, Moyynty, Shet, Karaganda Region, Kazakhstan