Zinnwaldite Deposit topotype - CINOVEC (ZINNWALD), ERZGEBIRGE, BOHEMIA - Czech republic (6 × 6 cm). — Photo: Didier Descouens · CC BY-SA 4.0
Zinnwaldite
A lithium-iron mica — technically a siderophyllite-polylithionite series rather than a valid species.
Intro adapted from Wikipedia (CC BY-SA).
Zinnwaldite is a mineral group, with the chemical formula KLiFe²⁺Al(AlSi₃)O₁₀(F,OH)₂.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 2.5–3; specific gravity 3; typically brown or gray or yellow; refractive index 1.625; optically biaxial.
Collections: Collector Favorites.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data and a Wikipedia introduction — a full written entry hasn’t been published yet.
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