Fluorite , cleavage

Analytical Methods. Fluorite is readily identified by its crystal shape, usually simple cubes or interpenetrating twins, by its prominent octahedral cleavage, its relative softness, and the production of hydrogen fluoride when treated with sulfuric acid, evidenced by etching of glass. The presence of fluorite in ore specimens, or when associated with other fluorine-containing minerals, may be deterrnined by x-ray diffraction. 

BARYTOCALCITE. This mineral is a carbonate of barium and calcium il crystallizes in the monoclinic system but occurs massive as well. Il lias a perfect cleavage parallel to the prism and one, less perfect, parallel to the base fracture, sub-conchoidal brittle hardness, 4 specific gravity, 3.66-3.71 luster, vitreous color, white or gray or may be greenish or yellowish transparent to translucent. Barytocalcite is found in Cumberland. England, associated with barite and fluorite. 

Cleavage, occurs when a crystalline substance breaks along planes that are parallel to crystal faces or structural planes (diamond, fluorite, calcite). 

Salts are important in the processing of some natural materials and may be found as residues on or in objects. Fluorite, which is also called fluorospar, is commonly used for carvings, particularly in Asia. The translucent pastels of this material make it attractive, but its softness and perfect cleavage combine to make fluorite objects very fragile. 

Halide Fluorite (fluorospar) CaF2 All colors 3.18 1.433 4 Perfect cleavage in four directions... 

For ceramic use, the most important mineral containing fluorine is fluorite (CaF2) which occurs in fluorspar. Natural deposits have a purity of 90-98% with silica as the principal impurity. Fluorite mineral powders have angular surfaces which result from cleavage and conchoidal fracture of the mineral [14]. Fluorspar is used in many forms of optical glass of low index of refraction and in enamels. 

Fluorite, fluorspar CaFj (Figure M75) Crystalline cubes with octahedral cleavage. Found in different colors (often blue or purple). It is the principal ore mineral of fluorine. It is used in the manufacture of hydrofluoric acid, and as a flux in the metallurgical and glass industries... 

In the [101] direction formed by a hexahedral (010) face and the cleavage (111) plane of fluorite... 

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