Characteristics and evaluation of diamond raw materials

Diamond is one of the most beautiful minerals, created by nature itself. Diamond is a mineral, which owing to its peculiar unique features, such as exceptional esthetic beauty, bright shining, wonderful light refraction, strong light dispersion, unordinary chemical resistance inertness, unsurpassed hardness, has occupied the leading position among all the precious stones for years. Brilliant, created as a result of skilled faceting of a diamond, is a unique adornment for women.
Average content of diamonds in kimberlites constitutes about 0,5 carats per 1 m3 of mining rock, in placer — about 0,25-0,5 carats per 1 m3. Basic diamond kimberlites are located in Russia and SAR. In general African continent is rich in natural and gravel deposits of diamonds (including offshore fields). In addition to SAR there are diamonds in Zaire, Botswana, Angola, Namibia, Ghana, Sierra-Leone and other countries. Gravel deposits and natural rich fields are located in Australia. There natural fields are represented as tube-like vertical bodies, but filled in with lamproite — magnetic rock, which in its content is similar with potassium high-alkali basalts (content of K20 up to 10% and more).
The name of the fields is usually associated with the names of large kimberlitic pipes, with diameter of 0,5 km. For instance, «Kimberly» is a group of diamond fields in SAR. It has been developed since 867. The area is up to 195 thou. m2; including 15 kimberlitic pipes. Basic center of production is Kimberly city.
«Premier» is a diamond field in SAR. Kimberlitic pipe is 880x500m. By the way, it is there that the largest diamond «Kuhllinan» of 3106 carats was produced.
In Tanzania there is a huge pipe «Mvadui» with diameter of 1,5 km being developed; pipes with diameters of more than 1 km are known in Botswana; large «Mote» pipe is located is Lesotho.