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Calcite (Photo) [abbr. Cal ]

Year of discovery: AD79 (World), 1875 (Japan)

Locality list: 4,094 localities of calcite

• CaCO₃
• [Ca²⁺][CO₃]^2-

• Class: Calcite group
• Class: Carbonate
• Variety: Aphrite (Lamellar)
• Variety: Manganoan calcite (+Mn)
• Soluble in: HCl (with bubbles)
• Magnetism: Diamagnetic
• Fluorescence: UV excitation (Blue, Green, Yellow, Red), Phosphorescence, Cathodo luminescence
• Phase transition: Formed on transition of heated Vateirte above 440 degree or in boiling water.
• Phase transition: Formed on transition of heated Aragonite above 400 degree.
• Formed on dehydration of Ikaite.
• Formed by reaction with water of dehydrated powder of Gaylussite.
• Formed by alteration of Priceite.
• Substitution pseudomorph: Replace Cerussite.
• Substitution pseudomorph: Replace Ikaite or Gaylussite. (Glendonite)
• Substitution pseudomorph: Replaced by Cerussite, Goethite, Manganite, Malachite, or Dolomite.
• Formed at temperatures lower than 50 degree under ambient pressure and acidic condition. Aragonite is formed at temperatures greater than 50 degree under ambient pressure and acidic condition
• Aragonite is frequently changed to calcite.

• Polymorph: Aragonite (Orthorhombic), Vaterite (Hexagonal)

• Ca => Mn: Rhodochrosite (Series)
• Ca => Mg: Magnesite
• Ca => Fe: Siderite
• Ca => Cd: Otavite
• Ca => Zn: Smithsonite
• Ca => Ni: Gaspéite (Gaspeite)
• Ca => Co: Spherocobaltite
• Ca => Ba: Witherite
• Ca => Sr: Strontianite
• Ca => Pb: Cerussite
• Ca => Na₂: Gregoryite

• Ca₂ => CaBa: Barytocalcite, Alstonite, Paralstonite
• Ca₂ => CaMn: Kutnohorite
• Ca₂ => CaFe: Ankerite

• [] => 6H₂O: Ikaite
• [] => H₂O: Monohydrocalcite

• Color: White-Colorless. Brown, Blue, Green, Pink by impurities.
• Streak: White
• Luster: Vitreous
• Diaphaneity: Transparent, Translucent

• Habit: Rhombohedral, Scalenohedral, Nail head, Pyramidal, Prismatic

• Cleavage: Perfect on {1011} (3 planes)
• Hardness: 3
• Density: 2.7

• System: Trigonal
• Group: (-3)m, R(-3)c
• Lattice: a=5.0, c=17.1

Etymology: Calx (lime) in Latin