Diamond is a colourless exceptionally hard mineral (but often tinted yellow, orange, blue, brown, or black by impurities), found in certain igneous rocks esp. the kimberlites of South Africa. It is used as a gemstone, as an abrasive, and on the working edges of cutting tools. Composition: carbon. Formula: C. Crystal structure: cubic. Name derived from the Greek adamas meaning invincible. Relative density 3.50- 3.52. Cleavage eminent along octahedral faces. Fracture conchoidal. Tenacity brittle. Lustre brilliantly adamantine. Refractive index 2.417- 2.419. Birefringence and pleochroism: none (cubic). Dispersion strong 0.044. Diamond crystals form as cubes, octahedra , the most common gem form, and dodecahedra. Colourless to yellow diamonds which have a strong absorbtion line in the violet end of the spectrum are members of the Cape series.

Where are diamonds found around the World? Natural diamond sources have been discovered in approximately 35 different countries around the World across several continents. Russia, Botswana and South Africa are the world’s major gem quality diamond producers and Australia is the major industrial diamond producer. The most notable diamond deposits are in Africa. Details of world locations are as follows:
* Africa : South Africa, Namibia, Botswana, the Democratic Republic of Congo, Angola, Tanzania and Sierra Leone
* Asia : India , China
* Russia : Siberia
* South America : Brazil
* Australia : Northern and Western Australia
* North America : Canada, United States - Arkansas (Crater of Diamond State Park) Colorado and Wyoming