ON A DIAMOND-BEARING PERIDOTITE AND ON THE HISTORY OF THE DIAMOND
By H. CARVILL LEWIS, M.A., F.G.S.
(Read at the Meeting of the British Association at Birmingham, 1886 ')
The discovery
of diamonds at Kimberley, South Africa, has proved to be a matter not
only of commercial but also of much geological interest. Here the
diamonds occur under conditions which are unlike those of any other
known locality7, and are worthy of special attention.
The
first diamond was found in South Africa in 1867, when a large specimen
was picked out of a lot of rolled pebbles gathered in the Orange River.
This led to the river diggings in the Orange and Yaal rivers, which
continue to the present time, but are now only worked at three or four
points.
In
1870, when perhaps 10,000 persons had gathered along the banks of the
Vaal River, the news came of the discovery of diamonds at a point some
15 miles away from the river where the town of Kimberley now stands.
These were the "so-called ' dry diggings,' which at first were thought
to be alluvial deposits, but have proved to be volcanic pipes of a
highly interesting character. In 1871 four mines were discovered in
close proximity to Kimberley, all of which have since become famous.
They are known as Du Toits Pan, De Beers, Kimberley, and Bulfontein
mines, all
