Crystal system Monoclinic | Formula(repeating unit) Cu11Mg2Cl18(OH)8•16H2O Space group P21/c | |
Crystal class Prismatic (2/m)(same H-M symbol) Unit cell a = 12.90, b = 16.42c = 11.96 [Å]; β = 113.69° (approximated) | ||
Feodosiyite is a very rare chloride mineral, just recently approved, with the formula Cu11Mg2Cl18(OH)8•16H2O. Its structure is unique. Feodosiyite comes from the Tolbachik volcano, famous for many rare fumarolic minerals. Chemically similar minerals, chlorides containing both copper and magnesium, include haydeeite, paratacamite-(Mg) and tondiite.
References
Feodosiyite Wikipedia(Text) CC BY-SA