兰西锰矿(Rancieite)因首次发现于法国兰西地区而得名。其化学式为(Ga,Mn,Mg)O·4MnO_2·3H_2O。1965年王典谋在我国陕西汉中天台山发现此矿物,1977年前后对此进行过比较系统的工作。该产地的样品呈褐棕色,质软。在光学显微镜下,样品由透明度差的鳞片状微小晶体(一般小于1μ)组成。该矿物分布较广,产于泥盆系(?)浅海相磷块岩-白云质锰矿床的风化壳中,与蜂窝状的硬锰矿互层出现于白云质锰矿层项部,形成锰帽堆积 Rancieite was named for its first discovery in the French Lanxi region. The chemical formula is (Ga, Mn, Mg) O · 4MnO 2 · 3H 2 O. In 1965, Wang Dianmou discovered this mineral in Tiantai Mountain, Hanzhong, Shaanxi Province, China. After 1977, it conducted relatively systematic work on this. The origin of the sample was brownish brown, soft. Under an optical microscope, the sample consisted of flaky, minute crystals (typically less than 1 μ) with poor transparency. The mineral is widely distributed and occurs in the weathering crust of the Devonian (?) Phosphorite-dolomitic manganese deposit, which interbedded with the honeycomb-like ductile magma occurs in the dolomitic manganese ore bed and forms a manganese-manganese-buildup