Crystal Stones
The masses are calcareous or dolomitic rocks that have been recrystallized by intrinsic factors, such as temperature and pressure, and are therefore metamorphic rocks. The main minerals that form most of the rocks are calcite. Chinese rocks also contain minerals such as quartz, graphite, hematite, Simonite, perite, and so on. In some Chinese rocks there is quartz, which increases with increasing hardness. If the stone is perfectly pure, it is white and luminous. Water absorption in porcelain or crystalline limestone is usually less than one percent. The porosity of this rock is very low, ranging from 0.5 to 1.2 percent