Loose Gemstones | Gem Art | Gem Stone Information



	even such stones were found only once in two or thiee years. Stones exceeding 100 carats in weight were seldom found. The 'Star of the South' weighed in the rough 254-5 carats, though considered a large stone. There were greater chances of finding larger diamonds in the Indian deposits and a number of stones exceeding 100 carats in weight were obtained. As most of the stones are known only in the cut condition, their original weight could only be estimated. Of the stones known in their rough condition 'the Regent' in the French Crown jewels is the heaviest; its weight before cutting was 410 carats and when cut yielded a beautiful brilliant of 136.875 carats. The 'Great Moghul' is supposed to have weighed originally 767.5 carats. The South African fields yielded stones of up to 150 carats in weight more frequently, and some were of several hundred carats. The largest stone discovered was at the Cape in 1893, which weighed 971.75 carats. On 13th August, 1938, in the Santo Antonio river a pure blue-white diamond weighing 726-6 carats was obtained and named the Vargas diamond in honour of the President of Brazil. It was cut in the U.S.A. and divided into twenty-three stones. III. Genesis Diamond has been found as a constituent of the earth's crust, e.g. occurs in the Kimberlite pipes of South Africa, the matrix being an altered peridotite; but it has also been found in extra-terrestrial bodies as meteorites. One such recent discovery is that of Canon Diabolo of Arizona, where a meteorite that fell recently contained diamonds as was proved by X-ray. But diamonds have been found mostly in secondary deposits, e.g. sands and gravels, which are often changed to firm conglomerates. * The discovery of the diamonds in" the 'dry diggings' of South Africa and their development into deep mines yielded a wealth of evidence on the genesis of the diamond. 72