Study on Gemmological Characteristics and Ore Genesis of Nephrite from Tanghe,Hebei Province

In recent years，a kind of nephrite from Tanghe has been discovered by some wonderful stone amateurs in Tanghe basins of Baoding，Hebei Province，which was called“Tangheyu”by the locals.However，it has not been studied whether the structure and quality of nephrite from Tanghe are corresponding with nephrite.In a field trip of local regional geology of the mine from Tanghe，the samples were collected.In this paper，the gemmological，mineralogical and petrology characteristics of the samples from Tanghe are systematically studied.It is roughly confirmed that the origins of nephrite from Tanghe are the contact zones between intermediate－acid granodiorite or granite and dolomitic marble，which locate in the stratum of Miwushan Group Jixian Period and Gaoyuzhuang Group Changcheng Period.