Transcript Diamonds
Diamonds “diamond” from the Ancient Greek term “adamas”, which means indestructible and unconquerable. History ► Diamonds were mined in India around 800 BC ► Diamonds were not mined when they were first found. They were found along rivers. ► In 1456 Louis de Bergueur discovered how to cut facets of a diamond. ► Until the 18th century India was the only known source for diamonds. ► Now diamonds are exported mostly from South Africa by a company called the De Beers. Diamond Physical Properties ► Hardness: Hardest gemstone known to man ► Clarity: Diamonds are transparent over a larger range of wavelengths ► Thermal Conductivity: Diamonds conduct heat better than anything else ► Melting Point: Diamond has the highest melting point (3820 degrees Kelvin) ► Lattice Density: The atoms of Diamonds in a tighter formation than any other substance. Natural Diamonds ► they are formed deep inside the earth's interior (high pressure and heat create the diamond crystal lattice) ► through the eruptions they were transported to the earth's surface. ► the eruptions were so fast and so powerful that the diamonds were brought straight to the surface. Synthetic Diamonds ► they were first produced in 1953 in Sweden ► they have been made by a process called High Pressure High Temperature synthesis (HPHT) ► at this process graphite is put into a huge hydraulic press at high temperatures and pressures, and with the addition of a metallic catalyst, converts to diamond over a period of a few hours. ► the diamond crystals that are produced by this method are useful as hard-wearing edges on cutting tools. Diamonds ► Structure: carbon ► Constitution: cubic system ► Colour: colourless, yellow, brown, green, blue, black ► Cut: white ► Hardness: 10 ► Density: 3,5 ► Other characters: the most adamant matter ► Finding place: South Africa, Russia, Brasil ► Availability: jewellery, hard-wearing edges on cutting tools Structure of Diamonds ► Diamond is carbon in its most concentrated form. ► Except for trace impurities like boron and nitrogen, diamond is composed solely of carbon. Carbon ► Classification: non-metallic ► Symbol: C (lat. Carboneum) ► Atomic number: 6 ► Group number: 14 ► Atomic weight: 12.0107 ► Electron configuration: ► Electrons per shell: 2, 4 1s2 2s2 2p2 Structure of diamond The carbon atom is connected to 4 other carbon atoms by strong chemical bonds, creating diamond's rigid crystal structure. Shapes of crystals ► ► ► ► ► octahedron cubo-octahedron (a combined form) dodecahedron macle twin cube The biggest synthetic diamond has 10 carat. Famous cuts of Diamonds round cut radiant cut princess cut Diamond has an aversion to water The Mohs scale of mineral hardness 1 2 3 4 5 6 7 8 9 10 Talc Gypsum Calcite Fluorite Apatite Orthoclase Quartz Topaz Corundum Diamond ! Thank you for your attention !