Zinnwaldite, KLiFeAl(AlSi3)O10(OH,F)2, potassium lithium iron aluminium silicate hydroxide fluoride is a silicate mineral in the mica group. The IMA status is as a series between siderophyllite (KFe2Al(Al2Si2)O10(F,OH)2) and polylithionite (KLi2AlSi4O10(F,OH)2) and not considered a valid mineral species. Name and discovery It was first described in 1845 in Zinnwald/Cinovec on the German-Czech Republic border. Occurrence It occurs in greisens, pegmatite, and quartz veins often associated with tin ore deposits. It is commonly associated with topaz, cassiterite, wolframite, lepidolite, spodumene, beryl, tourmaline, and fluorite. References Potassium minerals Iron(II) minerals Lithium minerals Aluminium minerals Monoclinic minerals Minerals in space group 9 Mica group