The
diamond is composed solely of pure carbon and is the hardest substance
known, being No. 10 on the Mohl scale. It is found in South Africa,
Brazil, India, Borneo, in the Ural Mountains, and in the United States.
The
ancient supply of diamonds came probably from India. Although we hear
of diamonds in very early times, yet the ancient Indian mines were
apparently the first source of supply and continued so until diamonds
were found in Borneo, which was only in small amounts, and later more
largely in Brazil. The Brazilian mines were discovered in 1727 and were
later mined extensively. Mr. Edwin W. Streeter, the London jeweler, in
his book published in 1879, states that about 1845 there were
twenty-five thousand people engaged in diamond digging in Brazil.
In
South Africa diamonds were first found in 1867. The first diggings —
they could hardly be called mines — were along the Vaal River. These
river diggings were of considerable extent,
