Cobalt it reacts slowly with mineral acids, and very slowly with moist, but not with dry, air. Common oxidation states of cobalt include +2 and +3, although compounds with oxidation states ranging from −3 to +5 are also known. A common oxidation state for simple compounds is +2 (cobalt(II)). These salts form the pink-colored metal aquo complex [Co(HO)] in water. Addition of chloride gives the intensely blue . In a borax bead flame test, cobalt shows deep blue in both oxidizing and reducing flames. Several oxides of cobalt are known. Green cobalt(II) oxide (CoO) has rocksalt structure. It is readily oxidized
Zhejiang Huayou Cobalt buying cobalt mined by hand in DRC entirely. Zhejiang Huayou Cobalt Huayou Cobalt Co., Ltd is primarily a supplier of cobalt, including cobalt tetroxide, cobalt oxide, cobalt carbonate, cobalt hydroxide, cobalt oxalate, cobalt sulfate, and cobalt monoxide. It is headquartered in the Tongxiang Economic Development Zone of Zhejiang, China. A subsidiary, Congo DongFang International Mining, has been involved in several controversies around sourcing of cobalt in the Democratic Republic of the Congo. According to a joint Amnesty International and African Resources Watch report, Congo DongFang International Mining, a subsidiary of Huayou Cobalt, sources cobalt from primitive "artisanal" mines in the