Sanbornite is a rare barium phyllosilicate mineral with formula BaSi2O5. Sanbornite is a colorless to white to pale green, platey orthorhombic mineral with Mohs hardness of 5 and a specific gravity of 3.74.

Sanbornite
Sanbornite (white) with celsian (gray)—Incline, Maricopa County, California
General
CategoryPhyllosilicate
Formula
(repeating unit)
Ba(Si2O5)
IMA symbolSabn[1]
Strunz classification9.EF.10
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPmcn
Unit cella = 4.62 Å, b = 7.68 Å
c = 13.52 Å; Z = 4
Identification
Formula mass273.50 g/mol
ColorColorless, White
Crystal habitPlaty modulated layers
CleavagePerfect
Mohs scale hardness5
LusterVitreous
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity3.74
Optical propertiesBiaxial (−)
Refractive indexnα = 1.597, nβ = 1.616, nγ = 1.624
Birefringenceδ = 0.0270
DispersionWeak
References[2][3]

It was first described from Incline, Mariposa County, California in 1932[4] and named for mineralogist Frank B. Sanborn (1862–1936).

See also

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Footnotes

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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. ^ Sanbornite: Sanbornite mineral information and data
  3. ^ Sanbornite Mineral Data
  4. ^ Rogers, A.F. (1932) Sanbornite, a new barium silicate mineral from Mariposa County, California. Amer. Mineral., 17, 161–172

References

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