Natural facing stone products are processed from natural rocks through mining, cutting, polishing and other processes. Because of their unique decorative properties, they are used as high-grade decorative materials. The classification of natural facing stone is mainly based on the hardness of stone, which is divided into granite, marble, slate, etc.
Natural facing stone
(1) Granite plate
Granite plates are made of granite by sawing, grinding, cutting and other processes. Granite slab is hard and dense, with high compressive strength, excellent wear resistance and good chemical stability. It is not easy to be weathered and metamorphosed, and has good durability. However, because granite contains quartz, crystal transformation will occur at high temperatures, resulting in volume expansion. Therefore, granite has poor fire resistance.
Granite is processed in different ways according to its different uses. The axe board commonly used by builders is mainly used for outdoor ground, steps, bases, etc; More than half of the machine planed boards are used on the ground, steps, cornices, steps, etc; Granite rough grinding plate is used for walls, columns, monuments, etc; Polished boards are mainly used for indoor and outdoor walls, floors, columns, etc. because of their distinctive colors and good luster.
(2) Marble slab
The main technical requirements for marble plate include: allowable deviation of specification and size, appearance quality, mirror gloss, bulk density, water absorption, dry compressive strength and bending strength.
Marble plates are used for the decoration of indoor columns, floors, window sills, service desks and elevator doors in hotels, exhibition halls, cinemas, shopping malls, libraries, airports, stations and other public building projects. They are ideal indoor high-grade decorative materials. In addition, it can also make marble murals, handicrafts, daily necessities, etc.
Marble plate has the advantages of small water absorption, good wear resistance and durability, but its weathering resistance is poor. Because the main chemical composition of marble is calcium carbonate, which is easy to be eroded, causing the surface to lose luster and become rough, thus reducing the decoration and use effect, it is generally not suitable for outdoor decoration except for individual varieties (sandstone and limestone mainly containing quartz).