Color: White, Gray, Reddish white, Brownish white, Gray.

Streak: White

Luster: Vitreous (Glassy)

Habit: Blocky - Rhombohedral - Crystal shape resembles rhomohedrons

Hardness: 3.5-4

Specific gravity: 2.8 - 2.9

Cleavage: Perfect on {1011}

Tenacity: Brittle

Twinning: n {0001}, common with re-entrant angles around the middle edges; on {1010} common; on {1120}, common, as complementary twins simulating holohedral symmetry; also as double twins by combination of this law and twins on {1010} or {0001}. On {1011}, rare. On {0221} as lamellae, especially in grains of dolomite marble

Crystal system: Trigonal

Crystal class: bar3

Unit cell a = 4.8012(1) Å, c = 16.002Å