Zinnwaldite makes up the bulk in this mineral group, that additionally includes crystalline iron-contaminated quartz and some very small crystals of cassiterite. Zinnwaldite is an utterly complex silicate mineral in the mica group, a potassium lithium iron aluminium silicate hydroxide fluoride, chemical formula KliFeAlO10 (OH, F)2. It features micaceous lamellae that may form rosettes. Provenance is Zinnwald in Saxony, Germany. Actual size of specimen is 100 mm across.