Diamond is allotrope of carbon. Carbon atom arrange in diamond cubic crystal structure. Diamond is hardest natural material found on earth. On moh hardness scale Hardness of diamond is 10. Hardness and crystalline structure occur due to high temperature and super high pressure on carbon in deep earth. When carbon Temperature goes to above 2000°F several miles under earth surface with million of tons weight then formation of diamond happens. However, this process situates several miles to hundreds of miles deep in earth. These diamonds and minerals travel to upper earth layers by eruption of volcanoes and any other natural changes in earth. In natural formation of diamond many other elements are along with carbon so small impurities like nitrogen admixed with carbon so impurities give colors to diamond. So, diamond can be found in Green, Yellow, Red, Blue, grey, black, brown, purple and pink Color with variant shades.
Luster and fluorescence are unique properties of diamond. Adamantine term is specifically used for diamond luster. Which means no distortion in reflected light from facet of diamond. Diamond emit prismatic colors like fire which make it eye catching beauty. Pure diamond is colorless and transparent and its refractive index is 2.419. Fluorescence is glowing on expose to UV light. Mostly diamonds glow under UV light with blue light. However, all diamonds do not have fluorescence property. And other glow with different shades like orange, yellow, pink and green.
Electrical and thermal conductance
Unlike other forms of carbon diamond is electrically insulator and thermally conductive. Diamond Electric insulation 1011 to 1018 Ω*m. However blue diamond contain boron contaminants so blue diamond is slightly conductive. Dielectric strength of diamond is more then 1MV/cm for pure or colorless diamond. Relative permittivity of diamond observed 5.5-10.5 at 25°C and 1KHz.
Thermal conductivity of diamond is near 2.2kW/(m·K) which is much higher than gold (318W / m-k), silver (429W/m. K), copper (385W/m. K), and aluminum (237 W/m. K).
Diamond melts near 4000°C due to very strong carbon atom bonding. Density of 3.5g/cm3 and specific gravity is 3.52. Diamond have high chemical and solvent resistance. Toughness of diamond is measured 2.0 MPa m1/2. Diamond can bear more than 603 G Pascals pressure without having crushed.
Diamonds found in stone form naturally. After cutting and shaping diamond gems use for jewelry, diamond rings etc. Mostly people demand colorless diamond, black diamond and blue diamond. Transparent diamond is costly due to it purity. How ever size and weight of gems also effects price. Due to diamond hardness in industry it is used for cutting and grinding of very hard materials. Diamonds are also use as semiconductors materials.