Celestite

Sample of red to blue, thick tabular euhedral Celestite crystals with a vitreous and pearly lustre. Largest Celestite crystal size: 1.0 cm x 0.6 cm x 0.2 cm. Celesite (SrSO4) can be white, colourless, bluish or reddish in colour. Lustre is vitreous or pearly and streak is white. Hardness is 3 to 3 1/2 and cleavage is perfect in one direction, good in a second direction and distinct in a third direction. Celesite usually occurs as thin or thick tabular crystals but can also be fibrous, cleavage masses, nodular, granular (rare) or lamellar.