Cerussite Composition, Crystallization & Structure
Composition. Lead carbonate, PbCO3 = Carbon Dioxide 16.5 lead oxide 83.5
Crystallization. Habit varied and crystals show many forms. Crystals often tabular parallel to brachy—pinacoid (Fig. 290). Frequently twinned, forming lattice-like groups with the plate crossing each other at 60| angles (pl. IC). Sometimes pyramidal in habit; also twinned in pseudohexagonal pyramids, frequently with deep reentrant angles in the prism zone.
Structure. In crystals or in granular crystalline aggregates; fibrous; granular massive; compact; earthy
Physical Properties. H. = 3-3.5. G. = 6.55 (high for a mineral with nonmetallic luster). Adamantine luster. Colorless, white or gray. Transparent to almost opaque.
Tests Easily fusible (1.5). With sodium carbonate B. B on charcoal gives globule of lead and yellow to white coating of lead oxide. Soluble in warm dilute nitric acid with effervescence. In C.T. usually decrepitates and is changed to lead oxide which is dark yellow when hot. Recognized by its high specific gravity, white color and adamantine luster.
Occurrence. An important and widely distributed lead ore of secondary origin, formed by the oxidation of galena in the presence of carbonated waters. Found in the upper and oxidized zone of lead veins, associated with galena, anglesite, sphalerite, smithsonite, silver ores, etc. Notable localities for its occurrence are Elms in Nassau; Mies, Bohemia; Nerchinsk, Siberia; on the island of Sardinia; in Tunis; at Otavi, Sout West Africa; Broken Hill, New South Wales; Phoenixville, Pennsylvania; Leadville, Colorado, various districts in Arizona; from the Organ Mts, New Mexico; in the Coeur D’Alene district in Idaho, etc.
Use. An important ore of lead.
Phosgenite, a chlorocarbonate of lead (PbCI) 2 CO3 tetragonal in crystallization, is a rate member of the Anhydrous Carbonate Division.Identifying Zinc Minerals Mining Equipment in South Africa Placer Deposits Crusher Electrical Lockout Features of Jaw Crushers What are Roll Crushers for: Applications STANDARD SCREEN ANALYSIS Changes in Financial Position Dolomite Composition, Crystallization & Structure Subsilicates - Humite Group, Calamine Composition Zinc Activation in CONCLUSIONS HorsePower drawn on new liners Identifying Fluorine Minerals Tourmaline Composition, Crystallization & Structure Crusher Maintenance Safety Tips
