Bertrandite (Be4(OH)2O(SiO3)2)

Chemical Properties

Transparent, colorless to pale-yellow, beryllium silicate with orthorhombic crystals.

Physical properties

Habit: well formed prismatic or tabullar hexagonal crystals, with pinacoidal {1010}, {0001}, or prism {1120} or pyramidal terminations.
Luster: vitreous (i.e., glassy).
Diaphaneity: translucent to transparent.
Color: colorless or pale yellow.
Streak: white.
Cleavage: [001] perfect, [110] distinct, [101] distinct.
Fracture: brittle.
Occurrence: commonly found in Be-bearing pegmatites and may be derived from the alteration of beryl.

Hazard

Carcinogen.

Industrial uses

Beryllia, and beryllium chemicals

Safety Profile

Confirmed carcinogen. Whenheated to decomposition it emits very toxic fumes of BeO.