Rhodizite

Formula: (K,Cs)Al₄Be₄(B,Be)₁₂O₂₈

Origin of name: from Greek for to be rose coloured

Crystal system: cubic

Crystal class: -43m

Twinning: 

Unit cell: a = 7.317 Å

Colour: colourless, white, yellowish white, yellow, grayish

Diaphaneity: 

Luster: vitreous to adamantine

Habit: crystals dodecahedral and tetrahedral, to 2 cm

Hardness: 8.5

Specific gravity: 3.44

Cleavage: 2; {111} and {-111} difficult

Tenacity: conchoidal

Streak: white

Synonyms/varieties:

Comments: