CUPRITE
CUPRITE Cuprite – Cu2O – is a very common oxide, typical of oxidation zones of Cu ores. It integrates Cu ores, but it is rarely the main ore mineral in the deposit. Cuprite crystals, quite rare, are cubic, octahedral, rhombododecahedral and of combined forms. The largest crystals reached 14 cm. There is a variety of […]
CALAMINE
CALAMINE “Calamine” is not a mineral, but rather a mining term applied to Zn ores composed of smithsonite, hemimorphite, and hydrozincite. For some authors, willemite is also part of “calamine.” The term was coined in 1747 by Johan Gottschalk Wallerius (Vallerius). It forms a generally white, transparent to translucent rock with a vitreous luster (it […]
CHALCEDONY
CHALCEDONY Chalcedony – SiO2 – is a common tectosilicate, a generic term given to all varieties of quartz popularly known as agate, jasper, chert, chrysoprase, onyx, pietersite and others. Scientifically, it designates clusters of aligned quartz microcrystals that form a fiber-like structure. These “fibers” can be of three types, formed by quartz crystals aligned parallel […]