Diamond (Ancient Greek: ἀδάμας; French, German: Diamant; English: Diamond), known as diamond in chemistry and industry. Diamond is a colorless crystal composed of carbon elements. It is the hardest natural substance known so far. The hardness of diamond comes from its amazing crystal structure and strong chemical atomic bonds. When the rock melts under extreme heat, it releases the carbon atoms of the diamond, which in the right environment, temperature and pressure combine to start forming a diamond. The earliest diamonds formed can be traced back to 909 million years ago, and some are even estimated to be 4.25 billion years old. Mineral-rich volcanic rocks, kimberlites or phloem volcanic rocks, are the main diamond conduits. Sediments containing diamonds leave the original deposition place to another place, which is called secondary deposition. For example, diamonds in Namibia are Travel 1,000 kilometers along the Orange River from the original South African deposit to Namibia. Small diamonds or "nanodiamonds" can also be found in meteorites, which formed earlier than the solar system. These diamonds may have come from supernovae, also known as stardust, and the myth that diamonds are the tears of the gods, becoming the intersection of science and poetry.