A kind of inorganic carbonate, mainly as a raw materials of ceramic and lithopone manufacturing. It’s specially used in transparent rubber products because of its refractive index similar to rubber. Bellow are the advantages in application in rubber：

1. It is able to increase the thermal conductivity glue, improve the thermal conductivity and the curing rate, especially suitable for hot air vulcanization process.
2. It can improve the stability of the shape of semi-finished products in the curing process, which is suitable for non-model products (such as the based products which is the use of continuous vulcanization technology).