Fluorite on Barite

Sample of numerous, colourless, vitreous dodecahedral euhedral Fluorite crystals on white compact Barite with a pearly lustre. Fluorite has been sprayed with Silicone. Largest Fluorite crystal size: 0.7 cm x 0.7 cm x 0.5 cm. Fluorite (CaF2) can be violet, blue, green, yellow, brown, bluish black, pink, rose-red, white or colourless. Lustre is vitreous and streak is white. Hardness is 4 and cleavage is perfect in four directions forming an octahedron. Fluorite usually occurs as cubic or penetration twins but can also be octahedral, dodecahedral, cleavage masses, granular or columnar. Barite (BaSO4) can be white, grey, colourless or shades of yellow, brown, red or blue. 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 and distinct in a third. Barite usually occurs as tabular crystals but can also be prismatic, divergent groups, compact, lamellar, fibrous or granular.