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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

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CERULEITE


CERULEITE (Ceruleit—Ceruléite—÷ерулеит) (Dufet, H., 1900), from Lat. “caeruleus” – azure, referring to its color. Arsenate – Cu2Al7[(OH)13|(AsO4)4]·12H2O, triclinic system. Hardness 6.5. Density 2.7-2.8. Dull luster. Ceruleite is a rare mineral, represented with cryptocrystalline masses only. Non-transparent. Color: light bluish-blue. It is found at copper deposits. At first it was discovered in Chile, in the Antofagasta Prov at the Emma Luisa mine, near El Huanaco, where it was extracted in the form of concretion up to 10 cm. in cross-section. When polished, ceruleite gets brighter in color. Under heating up to 250°C it is dehydrated and becomes light bluish-green. However, because of its high porosity, ceruleite should be improved with the method of impregnation, through which they receive stabilized ceruleite. It is cut in cabochon, it resembles turquoise and it is used for its imitation.
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