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Molybdite

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Molybdite
Molybdite on molybdenite from the Questa Molybdenum Mine (size: 11.0 x 6.7 x 4.1 cm)
General
CategoryMineral
Formula
(repeating unit)
MoO3
IMA symbolMyb[1]
Strunz classification4.EA.10
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPbnm
Unit cella = 3.96 Å, b = 13.85 Å,
c = 3.69 Å; Z = 4
Identification
ColorLight greenish yellow to nearly colorless
Crystal habitFlattened needles or thin plates may occur in aggregates
CleavagePerfect on {100}, district on {001}
TenacityFlexible
Mohs scale hardness3 - 4
LusterAdamantine
StreakWhite
DiaphaneityTransparent
Specific gravity4.72
Optical propertiesBiaxial (+)
BirefringenceHigh
2V angleLarge
References[2][3][4][5]

Molybdite is the naturally occurring mineral form of molybdenum trioxide MoO3. It occurs as yellow to greenish needles and crystallizes in the orthorhombic crystal system.

Discovery and occurrence

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Molybdite was first described in 1854 for and occurrence in quartz veins in the Knöttel area of Krupka, Ore Mountains, Bohemia (today in the Ústí nad Labem Region of the Czech Republic.[4] It occurs in vein cavities and as coatings in molybdenite ore veins and quartz topaz greisens. Associated minerals include molybdenite, betpakdalite and quartz.[3] The similar mineral ferrimolybdite is often misidentified as molybdite.[3]

References

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  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ "Molybdite". Mineral Atlas (database record). Retrieved 2023-01-15.
  3. ^ a b c Molybdite on the Handbook of Mineralogy
  4. ^ a b "Molybdite". www.mindat.org. Hudson Institute of Mineralogy. Retrieved 2023-01-15.
  5. ^ "Molybdite Mineral Data". www.webmineral.com. Retrieved 2023-01-15.