Chemical composition: AlSiO, Small amount of Fe may be present.
(i) Form: Long blade-shaped, sometimes form parallel or radiating aggregates.
(ii) Colour: White, brown, gray and pale green.
(iii) Lustre: Vitreous.
(iv) Streak: White.
(v) Hardness: 6-7.
(vi) Cleavage: Perfect but rarely seen.
(vii) Fracture: Uneven.
(viii) Specific gravity: 3.23.
(ix) Diaphaneity: Transparent to translucent.
Use: Manufacture of refractory bricks.