ˈtsinˌvälˌtīt noun
( -s )
Etymology: German zinnwaldit, from Zinnwald, Bohemia, its locality + German -it -ite
: a pale violet, yellow, brown, or dark gray mineral K 2 (Li,Fe,Al) 6 (Si,Al) 8 O 20 (OH,F) 4 that consists of mica containing iron and lithium