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Ore minerals in IOCG deposits are typically copper-iron sulfide chalcopyrite and gangue pyrite, forming 10–15% of the rock mass. Supergene profiles can be developed above weathered examples of IOCG deposits, as exemplified by the Sossego deposit, Para State, Brazil , where typical oxidised copper minerals are present, e.g.; malachite ...
A native platinum nugget, Kondyor mine, Khabarovsk Krai Platinum-palladium ore, Stillwater mine, Beartooth Mountains, Montana, US Sulfidic serpentinite (platinum-palladium ore) from Stillwater Mine, Beartooth Mountains, Montana, USA. Platinum is an extremely rare metal, [26] occurring at a concentration of only 0.005 ppm in Earth's crust.
Samarium is a rare earth element with a hardness and density similar to zinc. With a boiling point of 1,794 °C (3,261 °F), samarium is the third most volatile lanthanide after ytterbium and europium and comparable in this respect to lead and barium ; this helps separation of samarium from its ores.
Primary cobalt deposits are rare, such as those occurring in hydrothermal deposits, associated with ultramafic rocks, typified by the Bou-Azzer district of Morocco. At such locations, cobalt ores are mined exclusively, albeit at a lower concentration, and thus require more downstream processing for cobalt extraction. [93] [94]
The half-chord version of the sine function was developed by the Indian mathematician Aryabhatta. Brahmagupta's theorem (598–668) states that AF = FD. Zero – Zero and its operation are first defined by (Hindu astronomer and mathematician) Brahmagupta in 628. [169]