Borax (mineral)

Borate mineral
(repeating unit)Na2B4O5(OH)4·8H2OIMA symbolBrx[1]Strunz classification6.DA.10Crystal systemMonoclinicCrystal classPrismatic (2/m)
(same H-M symbol)Space groupC2/c (no. 15)Unit cella = 11.8790(2) Å,
b = 10.6440(2) Å,
c = 12.2012(2) Å;
β = 106.617(1)°; Z = 4IdentificationColorColorless or whiteCrystal habitAs prismatic crystals or as massive encrustationsTwinningRare on {100}CleavagePerfect on {100}, less perfect on {100}, very poor on {010}FractureConchoidalMohs scale hardness2 to 2.5LusterVitreous to resinous to earthyStreakWhiteDiaphaneityTranslucent to opaqueSpecific gravity1.715Optical propertiesBiaxial (-)Refractive indexnα = 1.4466 nβ = 1.4687 nγ = 1.4717Fusibility1.5Diagnostic featuresFroths on heating, producing a yellow flameSolubilitySoluble in waterReferences[2][3][4][5]

Borax (Na2B4O5(OH)4 · 8 H2O[2]) is a borate mineral found in evaporite deposits of alkaline lacustrine environments and as a surface efflorescence in arid regions. It is the chief mineral mined from the deposits at Boron, California and nearby locations, and is the chief source of commercial borax.[5]

Borax first reached Western civilization as tincal mined from deposits in Tibet.[5] The term borax comes from the Arabic bauraq, meaning white.[3]

Occurrences

The most extensive deposits are in Kirka, Turkey. Borax is also mined in the Andes Mountains of Argentina, Bolivia, and Chile. However, the greatest production is from the deposits in California.[5]

Uses

Natural occurrences of the mineral are an important source of commercial borax, which is used for the manufacture of glass fibers, in cleaning agents, as an antiseptic, and as a flux in metallurgy and solvent for metal oxides.[5]

See also

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 Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Borax" (PDF). Handbook of Mineralogy. Retrieved 17 June 2022.
  3. ^ a b Borax, Mindat.org, retrieved 17 June 2022
  4. ^ Sinkankas, John (1964). Mineralogy for amateurs. Princeton, N.J.: Van Nostrand. pp. 382–383. ISBN 0442276249.
  5. ^ a b c d e Klein, Cornelis; Hurlbut, Cornelius S. Jr. (1993). Manual of mineralogy: (after James D. Dana) (21st ed.). New York: Wiley. pp. 421–422. ISBN 047157452X.


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