Abstract
A DIAMOND of fine quality was found in January by Jacobus Jonker in South Africa in the Elandsfon-tein alluvial diggings on a tributary of the Pienaars River, near the Premier diamond mine and northeast of Pretoria. The weight is given as 726 carats (145.2 gin.). There is no evidence to support the suggestion that this new ‘Jonker’ diamond is the missing portion of the ‘Cullinan’ diamond, which was found in 1905 in the yellow ground in the wall of the Premier mine at a depth of 18 ft. beneath the surface. The ‘Cullinan’ weighed 621.2 gm. (3106 metric carats), and, as shown by the large cleavage surface, it was evidently only a portion (perhaps rather more than half) of a larger crystal. Diamonds sometimes become fractured during the eruption of the kimberlite magma into the pipes. Other large stones, but of doubtful quality, have been recorded from the Premier mine, namely one of 1640 carats in 1912, another of 1500 carats in 1919, and another of 1195½ carats in 1924. The first of these weighings would be against the English carat of 205.304 mgm., and the last two presumably against the metric carat of 200 mgm. The next largest stone is the ‘Excelsior’ found in 1893 in the Jagersfontein mine in Orange Free State, which in the rough weighed 199.04 gm. With the older diamonds there still exists an unfortunate confusion in the weights when expressed in carats. The re-cut ‘Koh-i-Noor’, usually listed as 1061 carats, weighs 21.786 gm. or 108.93 metric carats. A mass of carbonado (a compact aggregate of small crystals of diamond) found in Bahia in 1895 weighed 630 gm.
Article PDF
Rights and permissions
About this article
Cite this article
Another Large South African Diamond. Nature 133, 131 (1934). https://doi.org/10.1038/133131a0
Issue Date:
DOI: https://doi.org/10.1038/133131a0