Sassolite

Mineral form of boric acid
(repeating unit)H3BO3IMA symbolSso[1]Strunz classification6.AA.05Crystal systemTriclinicCrystal classPinacoidal (1)
(same H-M symbol)Space groupP1Unit cella = 7.02 Å, b = 7.06 Å
c = 6.59 Å; α = 103.65°
β = 101.11°, γ = 59.98°; Z = 4IdentificationColourWhite to gray, may be pale yellow from included sulfur or pale brown from included iron oxides; colourless in transmitted lightCrystal habitAs scaly pseudohexagonal crystals; ncrustations; platy; tabular; may be stalactiticTwinningAround [001] as twin axis, commonCleavagePerfect on {001}, micaceousTenacitySectileMohs scale hardness1LustreVitreous to pearlyStreakWhiteDiaphaneityTransparentSpecific gravity1.46–1.50Optical propertiesBiaxial (−)Refractive indexnα = 1.340 nβ = 1.456 nγ = 1.459Birefringenceδ = 0.1192V angleMeasured: 5°, Calculated: 16°SolubilitySoluble in waterReferences[2][3][4]

Sassolite is a borate mineral, specifically the mineral form of boric acid. It is usually white to gray, and colourless in transmitted light. It can also take on a yellow colour from sulfur impurities, or brown from iron oxides.[2]

History and occurrence

Its mineral form was first described in 1800, and was named after Sasso Pisano, Castelnuovo Val di Cecina, Pisa Province, Tuscany, Italy where it was found.[4] The mineral may be found in lagoons throughout Tuscany and Sasso.[3] It is also found in the Lipari Islands and the US state of Nevada. It occurs in volcanic fumaroles and hot springs, deposited from steam, as well as in bedded sedimentary evaporite deposits.[2]

See also

  • Earth sciences portal

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. ^ a b c Handbook of Mineralogy
  3. ^ a b Webmineral.com
  4. ^ a b MinDAT

External links

Media related to Sassolite at Wikimedia Commons


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