Barite, Fluorite and Quartz

Violet, cubic subhedral Fluorite with a vitreous lustre intertwined with white-reddish tabular Barite. Small, colourless vitreous granular Quartz crystals surrounding Barite and Fluorite. Sample comes from a pegmatite. Barite (BaSO4) can be white, grey, colourless, or shades of blue, red, yellow or brown. Lustre is vitreous or pearly and streak is white. Hardness is 3 to 3 1/2. Barite usually occurs as thin or thick tabular crystals that can also be prismatic, compact, lamellar, fibrous or granular. Quartz (SiO2) can be a variety of colours from white to purple. Lustre is vitreous or greasy and streak is white. Hardness is 7. Quartz usually occurs as long or short prismatic crystals that are terminated by double rhombohedrons and have striations crosswise. Quartz can also be granular, compact or disseminated. Fluorite (CaF2) can be violet, blue, green, yellow, brown, bluish black, pink, rose-red, white or colourless. Lustre can be vitreous and streak is white. Hardness is 4 and cleavage is perfect in four directions forming an octahedron. Fluorite usually occurs as cubes or penetration twins but can also occur as granular or columnar forms. Smallman Collection