Hanksite

Hanksite
Hanksite crystal from Searles Lake
General
CategorySulfate minerals, sulfate carbonate
Formula
(repeating unit)
Na22K(SO4)9(CO3)2Cl
IMA symbolHks[1]
Strunz classification7.BD.30
Crystal systemHexagonal
Crystal classDipyramidal (6/m)
H–M symbol: (6/m)
Space groupP63/m
Unit cella = 10.465(21) Å
c = 21.191(43) Å; Z = 2
Identification
ColorColorless to pale yellow, may be grayish green due to clay inclusions
Crystal habitOccurs as short prismatic to tabular hexagonal crystals
CleavageGood on {0001}
FractureUneven
TenacityBrittle
Mohs scale hardness3–3.5
LusterVitreous to dull
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity2.562
Optical propertiesUniaxial (−)
Refractive indexnω = 1.481, nε = 1.461
Birefringenceδ = 0.020
Ultraviolet fluorescencePale yellow under LW UV
SolubilityReadily soluble in water
References[2][3][4]

Hanksite is a sulfate mineral, distinguished as one of only a handful that contain both carbonate and sulfate ions (a sulfate carbonate). It has the chemical formula Na22K(SO4)9(CO3)2Cl.

  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. ^ Handbook of Mineralogy.
  3. ^ Mindat.org.
  4. ^ Webmineral data.