In recent years, the use of Pietra grey, especially for the flooring of busy places or places that need flooring with very high resistance, has been very popular among interior designers. A black one-handed stone with white streaks that doubles the beauty of the space. The presence of these white streaks affects its price. The more one-handed stone and the smaller the amount of these streaks, the more expensive it will be. It is mostly used in lobbies, floors, kitchen countertops, bathrooms and toilets. Note that the space in which this type of stone is used is better to be full of light and not to be used in small spaces, and if used with high and appropriate lighting, it is better to neutralize the effect of darkness. Because the more light in the space, the more luxurious it will be. If this type of stone is used as paving, interior walls and stairs, in general, the spaces where the area is used is more, the type of Pietra grey slab is used. In cutting it, its size and size will be considered so that more uniformity can be seen after installation. Tasteful designers even use the white streaks used to design the space. At present, there are many mines of this type of stone in Iran, such as Lashtar, Najafabad, Marshall, Dehbid, etc., but the most famous that is world-famous is Lashtar, which has a lot of exports to different countries. Rejection of a period of time due to the impossibility of cutting slabs, demand and even exports decreased, but over time, with the creation of slab cutting, demand increased again, this stone has low water absorption and is an ax in flooring It has applications.