Monday, August 19, 2019

Diamonds :: essays research papers

A Diamond is one of the two natural minerals that are produced from carbon. The other mineral is Graphite. Even though both of these minerals are produced from the same element ,carbon, they have totally different characteristics. One of the most obvious difference is that Diamond is hard and Graphite is soft. The Diamond is considered to be the most hardest substance found in nature. It scores a perfect ten in hardness. Because of its hardness a tiny Diamond is used as a cutting and drilling tool in industry. Even the Greeks called the Diamond â€Å"adamas† which means unconquerable. Diamonds also conducts heat better than any other mineral .   Ã‚  Ã‚  Ã‚  Ã‚   Diamonds come in several different color shades such as, yellow, blue, green, or pink. One reason why a Diamond has different colors is through the processes involving heat and radiation. Another reason is that 99.5% of a Diamond is Carbon and the rest are different trace elements. These 0.5% of elements are the reason why a Diamond has different color shades. For example Nitrogen causes it to have a yellow tint , and Boron a blue shade. The pink color in some Diamonds are thought to be caused by deformation of the atomic structure of the diamond crystal. A pure Diamond , which would be 100% carbon, is colorless Diamonds were created million years ago, when the earth was formed, the material experienced pressure of 5million times the atmosphere at sea level and temperatures between 1000~1200degreesC. These conditions caused carbon in the layers inside the planet to crystallize into diamonds. The diamonds moved up to the earth’s surface through volcano eruptions. This is why many Diamond mines are near volcanoes. Diamonds occur in two types of rock: Kimberlite and Lamprolite. Diamonds are mostly found in South Africa, India, Brazil, Russia, Australia, and Arkansas. Right now about 100million carats are mined each year. Today the largest cut Diamond in the world is the Cullian I at 530.2ct . The unit cell of a Diamond is cube. Five carbon atoms form tetrahedra at the cube corners , at the centers of each of the cube faces, and at four sites within the cube. The carbon atoms are located at the center of each tetrahedron . The carbon tetrahedra are covalently bonded, which explains why diamonds are extremely hard. The toughness of the Diamond comes from four planar directions of weakness , it is called octahedral cleavage .

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