Minerals
Diamonds are a special crystallisation form of carbon atoms. Carbon is nature’s principal building block: plants, animals and mankind too consist of carbon compounds. Diamond crystals came into existence about 3 billion years ago, at a depth of 140 to 200 kilometres inside the earth; they originated from carbon which was exposed to very high pressure (up to 70,000 kg per cm2) at a very high temperature (up to 2000 degrees Celsius).
The crystal form
Like the double four-sided pyramid (octahedron), that is considered one of the most perfect forms to process. Crystalisation appears frequently in nature, for example: ice-crystal, rock-crystal or other gemstones.
The hardness
In 1822 the Austrian mineralogist Friedrich Mohs compiled a hardness scale for minerals. In 10 stages, running from soft to very hard. At the bottom is talc (1) at the top, diamond (10).
Reflection, refraction and dispersion
In cut diamonds, light is captured and reflected as in no other precious stone. The effect of reflection and refraction is called brilliance, the play of colours as result of dispersion is called fire. Sparkle or life is mentioned in connection with the light effect that arises when the diamond is moved in light.
Diamond and industry
About 5% of the total world production of diamonds is processed into jewellery diamonds: the rest is used for industrial purposes. Since the industrial revolution in the 19th century, diamonds, on account of their hardness, have had many applications: polishing discs, drills, chisels, but also in electronic appliances for drawing extremely thin and precise conducting wire, or in very precise medical instruments. In some industrial applications for diamonds, they are used up, and have to be replaced with new ones regularly. So there is an ongoing demand. Since the fifties of last century it has been possible to produce artificial diamonds. Nowadays 95 - 99% of diamonds used in industry are synthetic.
