Tian Huangshi is a rare type of Shoushan stone, and theoretically pyrophyllite (Al2[Si4O10](OH)2) belongs to monoclinic system. The theoretical value of its chemical composition: SiO 266.7%; H2O5%； Al2O328.3%； Fe2 O31.7%; Cao is about 0.3%. It may also contain trace amounts of K, Mn, Ti, Zr ......... The change of the main color of Shoushan Stone is related to the change of the proportion of Fe2,O3,MgO etc. in its chemical composition. Molten sulfur is about 2 degrees, and its specific gravity is 2.5. The refractoriness is about 1700 degrees C ..