Goosecreekite

Formula:  CaAl₂Si₆O₁₆ ^.5H₂O

Origin of name:   From locality, Goose Creek Quarry, Virginia

Crystal system:  Monoclinic

Crystal class:  2

Twinning:

Unit cell: a = 7.45 Ǻ, b = 17.4 Ǻ, c = 7.3 Ǻ, β = 105.7°

Colour:   Colourless to white

Diaphaneity:

Luster:  Vitreous

Habit:  Crystals, imperfect, small; polycrystalline aggregates

Hardness:  4.5

Specific gravity:   2.21

Cleavage:  1; {010} perfect

Tenacity:

Streak:  White

Synonyms/varieties:

Comments:  Dimorphous with epistilbite