Saliotite

Saliotite is a rare colorless to pearl white phyllosilicate mineral in the smectite group with formula (Li,Na)Al3(AlSi3O10)(OH)5.[2] It is an ordered 1:1 interstratification of cookeite and paragonite. It has perfect cleavage, a pearly luster and leaves a white streak. Its crystal structure is monoclinic, and it is a soft mineral with a hardness rated 2-3 on the Mohs scale.[2][3]

Saliotite
General
CategorySilicate mineral
Formula
(repeating unit)		(Li,Na)Al3(AlSi3O10)(OH)5
IMA symbolSal[1]
Strunz classification9.EC.60
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupC2/m
Unit cella = 5.15 Å, b = 8.91 Å
c = 23.83 Å; β = 94.23°; Z = 4
Identification
ColorColorless to white
CleavagePerfect on {001}
Mohs scale hardness2 - 3
LusterPearly
StreakWhite
DiaphaneityTransparent
Specific gravity2.75
Optical propertiesBiaxial (-)
Refractive indexnα = 1.580 - 1.590 nβ = 1.580 - 1.590 nγ = 1.590 - 1.600
Birefringenceδ = 0.010
2V angle30° to 50°
References[2][3]

Saliotite was first described in 1994 for an occurrence in an outcrop of high grade schist north of Almeria, Andalusia, Spain. It was named for French geologist Pierre Saliot.[2]

References
  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. Saliotite data on Mindat
  3. Saliotite data on Webmineral
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