Asbecasite

Formula:  Ca₃(Ti, Sn)As₆Si₂Be₂O₂₀

Origin of name:  From combination of symbols for elements in the composition: As, Be, Ca, Si

Crystal system:  Hexagonal

Crystal class:  3m

Twinning:

Unit cell:   a = 8.36 Å, c = 15.30 Å

Colour:  Lemon-yellow to bright yellow

Diaphaneity: Transparent

Luster:  Vitreous

Habit:  Crystals rhombohedral, up to 0.5 cm

Hardness:  6.5 to 7

Specific gravity:  3.70

Cleavage:  1; Rhombohedral

Tenacity:

Streak:

Synonyms/varieties:

Comments: Found on cleft faces in orthogneiss