Formula: (K,Cs)Al₄Be₄(B,Be)₁₂O₂₈

Species:

Colour: Colourless, white, greyish, yellowish; colourless in transmitted light

Lustre: Adamantine, Vitreous

Hardness: 8

Specific Gravity: 3.305 – 3.38

Crystal System: Isometric

Name: From the Greek, “rhodizein,” = “to be rose-coloured” in allusion to its property of turning a blowpipe flame rose-red. Do not confuse with rhodesite.

Co-Type Localities: Ministerskaya Yama Pit, Sarapulka, Beryozovsky, Sverdlovsk Oblast, Russia; Mor’s Pit, Shaitanka District, Rezhevsky District, Sverdlovsk Oblast – Russia

The potassium analogue of Londonite. Londonite-Rhodizite Series.
First described by Rose in 1834 without quantitative chemical data. A chemical analysis was made by Damour (1882) but later showed to be incomplete, lacking both Li and Be. Specimens from Madagascar without analysis should be labeled as londonite-rhodizite series.