Comparison between Laos Stone and Shoushan Stone

The appearance, chemical composition and mineral components of Laos stones have been studied and compared to Shoushan stone.The relative density of Laos stones is 2.52-2.65.Under microscope, the grain of dickite in Laos stone is coarser and a grain of kaolinite is finer.In the SEM, dickite has a good and coarser crystal with pseudo-hexagon, and kaolinite has a good flake crystal with finer grain and nacrite has a finer and poor crystal.By the XRD, Laos stones consist of kaolinite, dickite and nacrite; No phyrophyllite and illite have been found in the Laos stone samples.Therefore, Laos stones are similar to the Gaoshan group of Shoushan stone in their mineral component.However, mineral component statistics of the Laos stone samples indicated that the samples contain dickite making up over two thirds in the Gaoshan group of Shoushan stone and the samples contain kaolinite making up over two thirds in the Laos stone, which is more than three times as many as Shoushan stone.No kaolinite has been found in the Shoushan Tianhuang, while there are kaolinites in the all Laos stone samples.It is an important difference between Laos stone and Shoushan stone in their mineral components and lays foundation for identification of them with naked eyed and instrument.