Tschermigite

1+1⁄2 - 2LusterVitreous, silkyStreakWhiteDiaphaneityTransparent to translucentSpecific gravity1.645Optical propertiesIsotropicRefractive index1.458BirefringenceAnomalously birefringentSolubilityDeliquescentReferences[2][3][4]

Tschermigite is a mineral form of ammonium alum, formula NH4Al(SO4)2·12(H2O). It is found in burning coal seams, bituminous shale and fumaroles. Because of its extreme water solubility it is unlikely to persist except in the dryest of conditions. Discovered in 1852 at Cermiky, also known as Tschermig in Bohemia. It is colorless and named for where it was discovered.

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. ^ Handbook of Mineralogy
  3. ^ Tschermigite on Mindat
  4. ^ Tschermigite on Webmineral


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