Rhomboclase

Rhomboclase is an acidic iron sulfate mineral with a formula reported as H5Fe3+O2(SO4)2·2(H2O)[1] or HFe(SO4)2·4(H2O).[2] It crystallizes in the orthorhombic system and typically occurs as tabular crystals with a rhombic outline.[1] It occurs as transparent colorless, blue, green, yellow or grey crystals with a vitreous to pearly luster.[3]

Rhomboclase forms within the oxidizing environment of pyrite rich ore deposits and is reported as a post mine mineral of arid regions.[1]

It was first described in 1888 for an occurrence in Slovakia and was named from Latin, rhombus, rhomb, and Greek klasis, to break, for its crystal form and perfect basal cleavage.[2]

References

  1. ↑ 1.0 1.1 1.2 http://www.handbookofmineralogy.org/pdfs/rhomboclase.pdf Handbook of Mineralogy
  2. ↑ 2.0 2.1 http://www.mindat.org/min-3410.html Mindat
  3. ↑ http://webmineral.com/data/Rhomboclase.shtml Webmineral data