Space group R3c | Formula(repeating unit) see text Crystal system Hexagonal crystal family | |
Crystal class Hexagonal scalenohedral (3m)H-M symbol: (3 2/m) Unit cell a = 8.26, c = 126.59 [Å] (approximated) | ||
Wiklundite is a rare and complex arsenite-silicate mineral with the formula Pb2(Mn2+,Zn)3(Fe3+,Mn2+)2(Mn2+,Mg)19(As3+O3)2(Si,As5+O4)6(OH)18Cl6. The mineral characterizes in a large c unit cell parameter. It was found in Långban, Sweden - a home for many rare and exotic minerals.
Relation to other minerals
Structure of wiklundite is unique. A slightly chemically similar mineral, although lacking manganese and iron, is hereroite.
References
Wiklundite Wikipedia(Text) CC BY-SA