Porcelain or crystal is a mass of calcareous or dolomitic rocks that have recrystallized due to internal factors, such as temperature and pressure, and therefore are considered as metamorphic rocks in different places in terms
Porcelain or crystal is a mass of calcareous or dolomitic rocks that have recrystallized due to internal factors, such as temperature and pressure, and therefore are considered as metamorphic rocks in different places in terms