Ore be processed and what ore is of too low a grade to be worth mining. Metal ores are generally oxides, sulfides, silicates, or native metals (such as native copper) that are not commonly concentrated in the Earth's crust, or noble metals (not usually forming compounds) such as gold. The ores must be processed to extract the elements of interest from the waste rock and from the ore minerals. Ore bodies are formed by a variety of geological processes. The process of ore formation is called ore genesis. An ore deposit is an accumulation of ore. This is distinct from a
Pentlandite Thompson Belt, Canada, and a few examples from Brazil. Pentlandite, but primarily chalcopyrite and PGEs, are also obtained from the supergiant Norilsk nickel deposit, in trans-Siberian Russia. The Sudbury Basin in Ontario, Canada, is associated with a large meteorite impact crater. The pentlandite-chalcopyrite-pyrrhotite ore around the Sudbury Structure formed from sulfide melts that segregated from the melt sheet produced by the impact. Pentlandite is a catalyst for production of hydrogen and oxygen from water using electricity. It is said to be as effective at this as platinum, which is significantly rarer and more expensive. Pentlandite Pentlandite is an iron-nickel sulfide,