... major components are quartz ,feldspar, diopside , tremolite , actinolite and etc , which is recrystallized after silicification . It's origin ... & lucky symbolization . Steady physical and chemical property, waterproof ,acid and alkali resistance ,wear and corrosion resisting ,also prevent from mildewing ... The biggest size for rough Slab ? It's Egg shape and wrap with earth (you can refer to the ...