Crystal stone, like marble, is composed of calcite, except that, depending on the degree of metamorphism, the size of the crystals is sometimes larger than usual, visible to the eye crystal stone. Crystal like marble, is a type of metamorphic stone. Crystal stones may be composed of quartz, in which case the hardness of the stone increases. The reason for choosing this stone is the sound of breaking similar to crystal stone, which is created in a thickness of less than 2 cm. Crystal stone is sometimes formed with the mineral wollastonite.
Iran crystal is totally known in the world. Some of these types such as Azna are known as the most luxurious types of crystal stones in the world. Azna crystal stone, Laybid crystal stone, Aligudarz crystal stone, Aligudarz black crystal stone, Boroujerd cloud crystal stone, Palsandro crystal stone, Persian Scottish stone, Khomein crystal stone, Salmas crystal stone, Qorveh crystal stone, Sirjan crystal stone, Sirjan black crystal stone, Crystal stone Niriz, Mashhad icy flower crystal stone, Herat crystal stone are some of the best known persian marble types in Iran.