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Melkovite

A valid IMA mineral species
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04198010017271924952933.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
06566260017271924982995.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
00616810017271925017175.jpg
Melkovite

U-Mo occurrence, Shunak Mountains, Mointy Railway Station, Moyynty, Shet District, Karaganda Region, Kazakhstan
04198010017271924952933.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
06566260017271924982995.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
00616810017271925017175.jpg
Melkovite

U-Mo occurrence, Shunak Mountains, Mointy Railway Station, Moyynty, Shet District, Karaganda Region, Kazakhstan
06106150017271925041534.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
06566260017271924982995.jpg
Melkovite

Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy
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About MelkoviteHide

05502950017271925067575.jpg
Vyacheslav Gavrilovich Melkov
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
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.
Compare UM1990-22-MoO:CaHP.


Unique IdentifiersHide

Mindat ID:
2637
Long-form identifier:
mindat:1:1:2637:2

Similar NamesHide

BelkoviteA valid IMA mineral speciesBa3(Nb,Ti)6(Si2O7)2O12
MilkovoiteA valid IMA mineral species - pending publicationCu4O(PO4)(AsO4)

IMA Classification of MelkoviteHide

IMA status:
Approved
IMA Formula:
CaFe3+2Mo6+5O10(PO4)2(OH)12·8H2O
Approval year:
1968
First published:
1969

Classification of MelkoviteHide

Strunz-mindat (2026):
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
Dana 8th ed.:
49.4.3.1

49 : HYDRATED MOLYBDATES AND TUNGSTATES
4 : Compound Molybdates and Tungstates
Hey's CIM Ref.:
22.5.11

22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate

Mineral SymbolsHide

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

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

Physical Properties of MelkoviteHide

Lustre:
Waxy, Dull
Transparency:
Transparent
Colour:
Brownish yellow; lemon yellow
Hardness:
3 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
One perfect cleavage
Density:
2.969 - 2.973 g/cm3 (Measured)    2.851 g/cm3 (Calculated)

Optical Data of MelkoviteHide

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 MelkoviteHide

Mindat Formula:
[Ca2(H2O)15Ca(H2O)6][Mo8P2Fe3+3O36(OH)]
Element Weights:
Element% weight
O44.428 %
Mo36.754 %
Fe8.021 %
Ca5.756 %
P2.966 %
H2.075 %

Calculated from ideal end-member formula.
O
Mo
Fe
Ca
P
H
Elements listed:
Ca, Fe, H, Mo, O, P - search for minerals with similar chemistry

Crystallography of MelkoviteHide

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)°
Ratio:
a:b:c = 1.712 : 1 : 1.375
Unit Cell V:
2407 ų

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
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 EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]
47c : [Carbonates, phosphates, borates, nitrates]

Type Occurrence of MelkoviteHide

Type Locality:
ⓘ U-Mo occurrence, Shunak Mountains, Mointy Railway Station, Moyynty, Shet District, Karaganda Region, Kazakhstan
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.
Geological Setting of Type Material:
Oxidation zone of a molybdenite-fluorite deposit.
Associated Minerals at Type Locality:
AutuniteFerrimolybditeIriginiteJarosite

Synonyms of MelkoviteHide

Other Language Names for MelkoviteHide

Dutch:Melkoviet
German:Melkovit
Spanish:Melkovita

Relationship of Melkovite to other SpeciesHide

Member of:
Mendozavilite Group > Betpakdalite Supergroup
Other Members of Mendozavilite 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 AssociatesHide

Associations Based on Photo Data:
2 photos of Melkovite associated with JarositeKFe3+3(SO4)2(OH)6
2 photos of Melkovite associated with Iriginite(UO2)Mo2O7 · 3H2O
2 photos of Melkovite associated with FerrimolybditeFe2(MoO4)3 · nH2O
2 photos of Melkovite associated with FluoriteCaF2
2 photos of Melkovite associated with 'Unnamed (Hydrous Zr Molybdate)'Zr-Mo-O-OH
1 photo of Melkovite associated with MolybdeniteMoS2

Related Minerals - Strunz-mindat GroupingHide

8.DM.TomsquarryiteNaMgAl3(PO4)2(OH)6 · 8H2OTrig. 3m(32/m) : R3m
8.DM.ElliottiteNaMgAl3(PO4)2F6 · 9H2OMon. 2/m : B2/m
8.DM.Betpakdalite-FeFe[Fe3+2 (H2O)15(OH)2Fe3+(H2O)6][Mo8As2Fe3+3O37]Mon. 2/m : B2/m
8.DM.Penriceite[Mg(H2O)6][Na(H2O)2Al3(PO4)2F6] · H2OMon. 2/m : P21/b
8.DM.Betpakdalite-CaMg[Ca2(H2O)17Mg(H2O)6][Mo8As2Fe3+3O36(OH)] Mon. 2/m : B2/m
8.DM.Chinnerite[Mg(H2O)6]Na(H2O)2Al3(PO4)2F6Mon. 2/m : P2/m
8.DM.Sarrochite[Ca4(H2O)38][Mo8P2Fe3+3O37(OH)]Trig. 3m(32/m) : P3m1
8.DM.05EsperanzaiteNaCa2Al2(AsO4)2(OH)F4 · 2H2OMon. 2/m : P21/m
8.DM.05MoriniteNaCa2Al2(PO4)2(OH)F4 · 2H2OMon. 2/m : P21/m
8.DM.10AlexshubnikoviteCa2Cu9(AsO4)4(OH)9Cl(H2O)8 · 2H2OMon. 2/m : P2/b
8.DM.10TangdaniteCa2Cu9(AsO4)4(SO4)0.5(OH)9 · 9H2OMon. 2/m : B2/b
8.DM.10TyroliteCa2Cu9(AsO4)4(CO3)(OH)8 · 11H2OMon. 2/m
8.DM.15Betpakdalite-NaCa[Na2(H2O)17Ca(H2O)6][Mo6+8As5+2Fe3+3O34(OH)3]Mon. 2/m : B2/m
8.DM.15Betpakdalite-CaCa[Ca2(H2O)17Ca(H2O)6][Mo6+8As5+2Fe3+3O36(OH)]Mon. 2/m : B2/m
8.DM.20Phosphovanadylite-BaBa[V4+4P2O8(OH)8] · 12H2OIso. 43m : I43m
8.DM.20Phosphovanadylite-CaCa[V4+4P2O12(OH)4] · 12H2O Iso. 43m : I43m
8.DM.25YukoniteCa3Fe3+(AsO4)2(OH)3 · 5H2OOrth. mm2
8.DM.30UdumineliteCa3Al8(PO4)2O12 · 2H2O
8.DM.35Aldermanite[Mg(H2O)6][Na(H2O)2Al3(PO4)2(OH,F)6] · H2O Mon. 2/m : P21/b
8.DM.35'Azovskite'Fe3+3(PO4)(OH)6 or near
8.DM.35DelvauxiteCaFe4(PO4,SO4)2(OH)8 · 4-6H2O not confirmedAmor.
8.DM.40Santafeite(Na,Ca,Sr)12(Mn2+,Fe3+,Al,Mg)8Mn4+8(VO4)16(OH,O)20 · 8H2OOrth. mmm(2/m2/m2/m)
8.DM.55TapiaiteCa5Al2(AsO4)4(OH)4 · 12H2OMon.
8.DM.60Alcantarillaite[Fe3+0.5(H2O)4][CaAs3+2(Fe3+2.5W6+0.5)(AsO4)2O7]Orth. mmm(2/m2/m2/m) : Imma

Fluorescence of MelkoviteHide

Other InformationHide

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 MelkoviteHide

References for MelkoviteHide

Localities for MelkoviteHide

Showing 6 localities.

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.
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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.
Australia
 
  • Victoria
    • Rural City of Wangaratta
      • Everton
Victoria Museum Specimen
  • Western Australia
    • Ravensthorpe Shire
W.D. Birch (2002) +1 other reference
Chile
 
  • Atacama
    • Copiapó Province
      • Copiapó
        • Quebrada San Miguel
SEM-EDS by Joy Desor
Greece
 
  • North Aegean
    • Chios
      • Chios
Kanellopoulos et al. (2024)
Italy
 
  • Sardinia
    • Metropolitan City of Cagliari
      • Sarroch
Kampf et al. (2012)
Kazakhstan (TL)
 
  • Karaganda Region
    • Shet District
      • Moyynty
        • Mointy Railway Station
          • Shunak Mountains
Egorov et al. (1969) +2 other references
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