QUENSELITE
QUENSELITE Quenselite – PbMnO2(OH) – is an extremely rare hydroxide. It is not an ore, despite containing 66.59% Pb and 17.66% Mn by weight. It is probably more common than the few existing records suggest; it just wasn’t recognized because Mn ores, in general, are made up of minerals typically occurring in extremely small, submicroscopic […]
QUARTZ
QUARTZ Quartz – SiO2 – is a very common tectosilicate, the second most abundant mineral in terrestrial crustal rocks after feldspars, important as rock-forming mineral in igneous, metamorphic and sedimentary rocks. It is very resistant to alteration and therefore it is the main constituent of sand. Quartz crystals are usually combined forms; over 500 different […]