Mohs hardness 10, new Mohs hardness 15, microhardness 10000kg/mm2, which is 1000 times higher than that in time and 150 times higher than that in corundum. The hardness of diamond is directional. The hardness of octahedral crystal face is greater than that of rhombohedral crystal face, and the hardness of rhombohedral crystal face is greater than that of hexahedral crystal face. Diamonds (diamonds) are the highest grade, with the grade 10.

Diamonds come in various colors, ranging from colorless to black, of which colorless is particularly preferred. They can be transparent, translucent or opaque. Many diamonds are yellow, mainly because they contain impurities. Diamonds have high refractive index and strong dispersion.

Diamonds are generally granular. If the diamond is heated to 1000℃, it will gradually become graphite.

The crystal structure of diamond minerals belongs to equiaxed tetrahedron structure and has the same polar bond. Carbon atoms are located at the top and center of tetrahedron and have high symmetry. The carbon atoms in the unit cell are connected by homopolar bonds with a distance of 154pm. The common crystal forms are octahedron, rhombic dodecahedron, cube, tetrahedron and hexahedron.

Extended data:

The original diamond was discovered in India in 800 BC. No one dares to process the original diamond. Diamonds are considered to have the power to control the earth, which can protect the wearer and make it mysterious.

Only kings, queens and their followers can afford such a rare and beautiful diamond decoration. The natural state of diamonds is very precious. We have discovered and used diamonds for more than 2000 years. A Hungarian queen's crown is inlaid with uncut diamonds, which can be traced back to 1074 and is considered as the earliest form of diamond jewelry.

Diamond mines have been discovered all over the world. Among them, Australia, Congo, Russia, Botswana and South Africa are five famous diamond producing areas.

Diamond for geological drilling, petroleum drilling, diamond for wire drawing die, diamond for abrasive, diamond for dresser, diamond for glass cutting machine, diamond for hardness tester head and diamond for handicrafts.

References:

Baidu encyclopedia-diamond original stone

References:

Baidu encyclopedia-diamond