for the correctness of some of these determinations, as the crystals
were found in a mine under his personal supervision at Cherokee in
Butte County, where diamonds are known to have been found as early as
1853. Mr. George F. Kunz gives an interesting description of the
diamonds of California and the localities in which they are found.1
IN THE ORANGE RIVER COLONY
Koffyfontein Mine. —
This mine is situated in the Orange River Colony about 50 miles from
Kimberley. It contains about 1200 claims. The mine is well equipped,
and since the war has been worked on a large scale. The yield of the
ground is poor, averaging from 4 to 5 carats per 100 loads. The quality
of the diamonds is good, and they are valued at 55 shillings per carat.
The Lace Mine. —
The Lace Mine is situated in the neighborhood of Kroonstad in the
Orange River Colony. The yield of diamonds has been about 10 carats per
100 loads. The quality of the diamonds is poor.
DIAMONDS IN THE TRANSVAAL
is made on pages 162 and 163 that diamonds had been found in both the
alluvial along the Vaal River and in alluvial and in pipes at
Rietfontein near Pretoria. The Rietfontein mines are referred to by
Professor G. A. F. MolengraafF (see pages 134—136).
As the Transvaal mines have of late become a factor in the production of diamonds, a short history of them will be interesting.
properties of the Transvaal Diamond Mining Co. (now the Montrose D. M.
Co.) and the Schuller D. M. Co. were discovered in 1898, and the
remarks of Professor MolengraafF mentioned on pages 134—136 were in
reference to the nature of the diamond-bearing rock in these mines. The
Transvaal D. M. Co. is reported to have produced about 9000 carats from
11,500 loads of 16 cubic feet.
Schuller Company from its beginning to October, 1903, found 12,655
carats of diamonds from 38,015 loads. The diamonds in its mines occur
in the alluvial wash. Although the mines were discovered in 1898, there
is no record that the rock underlying the alluvial deposits contains
discovery of diamonds, even in small quantities compared with the
Kimberley output, gave an impetus to prospecting and company
1 "Gems and Precious Stones," by George F. Kunz, New York, 1892.