Vishnevite

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Vishnevite
Vishnevite from Scotland
General
CategoryTectosilicate
Formula
(repeating unit)
(Na,Ca,K)6(Si,Al)12O24[(SO4),(CO3),Cl2]2-4·nH2O
IMA symbolVhn[1]
Strunz classification9.FB.05
Crystal systemHexagonal
Crystal classPyramidal (6)
H-M symbol: (6)
Space groupP63
Unit cella = 12.7228(3)
c = 5.198(3) [Å]; Z = 1
Identification
ColorColorless, light blue, orange-yellow, white
CleavagePerfect
Mohs scale hardness5 - 6
LusterVitreous, pearly
StreakWhite
Optical propertiesUniaxial (-)
Refractive indexnω = 1.490 - 1.507 nε = 1.488 - 1.495
Birefringenceδ = 0.002 - 0.012

Vishnevite, or sulfatic cancrinite, is a mineral of the cancrinite group with the chemical formula (Na, Ca, K)6(Si, Al)12O24[(SO4),(CO3), Cl2]2-4·nH2O. It has hexagonal crystals.[2][3]

References[edit]

  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. ^ Fleischer, Michael & Mandarino, Joseph, "Glossary of Mineral Species", The Mineralogical Record, 1991
  3. ^ Webmineral data

External links[edit]