Gemmological Characteristics of Changhua Yellow Stone

The appearance of Changhua yellow stone from Zhejiang Province is much similar to that of Tianhuang stone from Shoushan,Fujian Province.In order to differentiate them,Changhua yellow stone samples are tested with the means of XRD,IR,and SEM.The results show that the main mineral composition of Changhua yellow stone sample is dickite,containing alunite as a minor mineral,while Tianhuang stone contains nacrite as the main composition or is a mixture of nacrite and dickite in varying proportions.Dickite in Changhua yellow stone sample appears to be flake and false hexagonal plate,but the structure of the main mineral composition of Tianhuang stone sample is aggregated lump.