This type of stone is considered as a subset of marble. It is mostly used in interior design to give luxury to various places such as hotels, lobbies, restaurant floors and toilets, etc. Which has a great impact on the beauty of this place. One of the Pietra grey mines is located 45 km south of the city of Isfahan. White veins are used in this stone and it has a very high abrasion ability, which gets a great effect by cleaning this stone and shining. That is why it is very effective in places with a lot of washing. The point to note about this type of stone is that using them in places exposed to direct sunlight causes the main color of these stones to change from black to light gray. So it is better not to use them in places like the facade of the building. The most famous type of this stone is Lashtar stone, which is world famous. Usually the price of this type of stone depends on various factors. For example, the uniformity of the color of the stone will increase its price, or even the thickness of the ordered stone, regular and more accurate cuts will affect its price. So in order to be able to have all these and even more in one stone, it is better to buy from reputable places. Variations in Lashtar marble go back to the place where it is to be used and the type of stone cutting. So before buying, it is better to use the free nite stone consultation to have the right choice with your use to be satisfied with your purchase many times over.