Stellerite

Formula: CaAl₂Si₇O₁₈.7H₂O

Origin of name: for G. Steller, German explorer

Crystal system: orthorhombic

Crystal class: 2/m 2/m 2/m

Twinning:

Unit cell: a = 13.60 Å, b = 18.22 Å, c = 17.68 Å

Colour: white to pale pink

Diaphaneity: 

Luster: 

Habit: crystals to 5 mm

Hardness: 3.5 to 4

Specific gravity: 2.13

Cleavage: 1; {010} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: member of the zeolite group