crystal of rhodizite, tourmaline var. rubellite : Tetezantsio village, Ampasagona, 12 km east of Antsongombato, FKT Antsentsindrano, Deptartementa Andrembesoa, — Photo: Parent Géry · CC BY-SA 3.0
Rhodizite
A rare caesium-beryllium borate — the 'caesium beryl' — from gem pegmatites.
Intro adapted from Wikipedia (CC BY-SA).
Rhodizite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula KBe₄Al₄(B₁₁Be)O₂₈.
It crystallizes in the cubic crystal system (space group P-43m). It is a member of the Rhodizite structural group.
Key properties: Mohs hardness 8; specific gravity 3.22–3.44; typically colorless or white or yellow or gray; white streak; Vitreous to slightly adamantine luster.
IMA symbol Rdz, grandfathered status — known before the IMA’s founding, named in 1834.
A rare late-stage accessory mineral in alkali-rich granite pegmatites.
It is found associated with Londonite, elbaite, spodumene, beryl, béhierite, albite, microcline, quartz.
Its name comes from the Greek for rose-colored, for the rose-red color the mineral imparts to the blowpipe flame.
Collections: Rare & Remarkable, Collector Favorites, Gemstones.