[{"from": "human", "value": "Describe this molecule. [S][=Co]"}, {"from": "gpt", "value": "The molecule is a sulfide of cobalt. Cobalt sulfide precipitates when aqueous solutions of cobalt(II) ions are treated with hydrogen sulfide. It is used as a catalyst for the industrial process called hydrodesulfurization, which is implemented on a large scale in refineries. Cobalt is a metallic element with the atomic number 27. It is found naturally in rocks, soil, water, plants, and animals. In small amounts cobalt is an essential element for life, as it is part of vitamin B12. However, excess exposure is known to exhibit toxic effects. (L29, L30, L480)"}]