Crystalline stones are kinds of limestone that have re-crystallized due to factors such as temperature and pressure under the earth surface, therefore crystals considered as metamorphic rocks. The internal structure of the stone and the granulation of the crystal stone are different from one quarry to another one. In some crystalline rocks, there is quartz, which increases the hardness of the rock. If the crystal stone is completely pure, it has a white color and brightness. The light gray to black color in these stones indicates the presence of carbonated materials in them.