Wiklundite is a rare[3] and complex arsenate arsenite-silicate mineral with the chemical 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.
[2] It was found in Långban, Sweden - a home for many rare and exotic minerals.
[2] A slightly chemically similar mineral, although lacking manganese and iron, is hereroite.
[5] This article about a specific silicate mineral is a stub.