Edingtonite

Formula:   BaAl₂Si₃O₁₀ ^. 4H₂O

Origin of name:   For Mr, Edington, Scottish discoverer of mineral

Crystal system:   Orthorhombic and tetragonal

Crystal class:   222

Twinning:   On {110} or about [001] axis

Unit cell: a = 9.534 Ǻ, b = 9.649 Ǻ, c = 6.507 Ǻ

Colour:  White, grayish, pink

Diaphaneity:

Luster:   Vitreous

Habit:   Crystals prismatic with pyramidal terminations; massive

Hardness:   4

Specific gravity:   2.78

Cleavage:   1; {110} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: