Parisite

(named after J. Paris, proprietor of the mine in Colombia where the mineral was discovered), a rare-earth fluorocarbonate mineral having the chemical composition Ca(Ce, La)₂ •[CO₃]₃F₂. It crystallizes in the trigonal system and occurs in crystal form and in solid, compact deposits and earthy masses. It has a hardness of 4.5 on Mohs’ scale and a density of 4,320–4,360 kg/m³. The mineral is usually brownish red or wax yellow, vitreous to waxy in luster, and translucent to transparent. It contains 30.56 percent Ce₂O₃, 10.44 percent CaO, 24.58 percent CO₂, and 7.07 percent F. Parisite generally occurs in hydrothermal deposits associated with alkali syenites and granites, although it also occurs as an accessory mineral in nepheline syenites and alkali pegmatites. It is associated with calcite, fluorite, bastnaesite, and other minerals.