The Kimberley Diamond Mine, South Africa
In the latter half of the nineteenth century, farmers, and especially their young children, would periodically find rough, alluvial diamonds. Washed up in river beds, these early diamond finds were rarely recognised for what they actually were and the gems often remained in the homestead to be used as playthings!
The Eureka Diamond
In late 1867, early 1868, a young boy named Erasmus Jacobs discovered a small white pebble on the banks of the Orange River which he showed to his father. His father in turn showed it to his neighbour who had the stone sent for analysis in Grahamstown. It was confirmed as a 21.25 carat diamond and was cut to form a 10.73 carat gem named the Eureka.
The Star of South Africa Diamond
In 1869 another significant find was made, this time by a shepherd known as Swartboy. Found on the Zandfontein Farm again near the Orange River, the crystal weighed an impressive 83.50 carats. In its cut form it weighed 47.69 carats and became known as the Star of South Africa.
Kimberlite diamond finds
That same year diamonds were discovered away from any of the river deposits in gravelly soil and weathered rock. This rock was named after the region in which it was found, Kimberley, and is today known as kimberlite. These diamond finds forced a rethink about previously held beliefs on diamond and its origin and led to the South African diamond rush.
The kimberlite near to the surface was soft and yellow. It could be fairly easily crushed to extract the diamonds. The land was divided up into ‘claims’ measuring some 30 foot square and worked on by the miners. As the miners dug deeper and deeper at different rates, the area became increasingly unstable and the claims were gradually expanded.
At between 17 and 27 metres the yellow ground began to turn blue. Thinking that they had reached the bottom of the diamond deposit, many miners gave up, but a few realised that the blue ground was simply unweathered yellow ground and that it still contained diamonds. The blue ground could be weathered deliberately over a period of months, or crushed by work gangs.
Between 1871 and 1914, 50,000 miners worked the mine with pick and shovel. By 1914 the Kimberley mine had yielded an incredible 14.5 million carats and had left a crater measuring 175 metres deep and 455 metres across. Nicknamed the ‘Big Hole’, it is now one of the largest man made craters on earth.
If you have any diamonds that you would like to sell then please contact Simon Rufus, diamond grader at Grand Auctions, Folkestone, Kent.