Diamond is a simple crystal composed of carbon element formed in the deep part of the earth under high pressure and high temperature, which refers to polished diamond. Diamond is a colorless octahedral crystal, which is composed of pure carbon and carbon atoms connected by tetravalent bonds. It is the hardest substance known to exist naturally at present.
Because the C-C bond in diamond is very strong, all valence electrons participate in the formation of valence bond, and there are no free electrons, so the hardness of diamond is very high, the melting point is 6900 degrees Fahrenheit, the ignition point of diamond in pure oxygen is 720 ~ 800 degrees Celsius, and in air it is 850 ~ 1000 degrees Celsius, which is non-conductive.
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Distribution of diamonds:
Diamond mines have been discovered all over the world. Among them, Australia, Congo, Russia, Botswana and South Africa are five famous diamond producing areas.
Dr Steven Hagarty, a geophysicist at the University of Massachusetts in the United States, studied the age of 1999 lava containing diamonds around the world and found that these lava containing diamonds were formed by magma ejected from various places in at least seven different periods in the past. The oldest lava was formed about 10 billion years ago.
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