Lead and selenium mainly exist in galena, clausthalite, and selenio-galena which occur as cell-filling of coal-forming plants and are of chemical-sedimentary origin.

铅和硒主要赋存在方铅矿、硒铅矿和硒方铅矿中，这3种矿物以植物胞腔充填形式出现，属于化学沉积成因。