Abstract: The Tianhuang samples from Shoushan rivulet in Fujian Province are studied respectively on the mineral components and micro-morphological characteristics of the body,"Luobosiwen" and weathering skin parts by means of XRD,SEM(EDX)and FTIR.The results show that the Tianhuang samples are mainly composed of dickite and nacrite of kaolin-group minerals,but some contain a little of illite and quartz.There is no kaolinite in the body and "Luobosiwen" parts,but found in the weathering skin part.The crystal size and crystal degree of kaolin-group minerals in the body of the Tianhuang samples are different.The boundary of some area could be observed between "Luobosiwen" and body parts.The kaolin-group minerals in the slick weathering skin part of Tianhuang gemstone lose their crystal morphology because of liquid-rock reaction and outside force action,but the kaolin-group minerals in the holes of facies are keeping the good crystal morphology.