A vast number of the diamonds found in these fields are tinged with a faint hue, generally yellow or faint brown. This peculiarity was also noticed with the yield of the Brazilian mines.
It is quite impossible to give a correct account of the quantity afforded by these mines up to the present time. It amounts to many millions of dollars, and is sufficiently large to produce a marked effect upon the market, but nothing like the panic which followed the discovery of the Brazilian mines. The value of the diamonds exported at Cape Town in 1871 is said to have been $7,500,000, but it was probably much greater.
Australia has afforded to the gold miners quite a number of small diamond crystals, and gem fields undoubtedly occur within its borders. Among the auriferous sands of the Maguarie River minute crystals have been picked by the careless miner from time to time, and other localities have also afforded specimens of the mineral, but no systematic search has yet been made for them. A number of these specimens of diamonds, although of minute form, were exhibited at Melbourne in 1865.
The islands of Java and Sumatra yield diamonds among their mineral treasures, but, strange to say, the island of Ceylon, which is the most remarkable gem deposit in the world, does not produce a single specimen. The island is not far distant from the gem districts of lower Bengal. The formation appears to be of the same character, but it is evident that the geological conditions which deposited the sapphire, the zircon, spinel, etc., differed from those required by the diamond.
CHAPTER IV.
ORIGIN OF THE DIAMOND.
The origin of this precious stone has been a favorite study with man from the earliest times of its history; and, as we have already stated, it has given birth to a multitude of hypotheses.
The peculiar fascination which attends the contemplation of the gems arises partly from their commercial distinction, as well as from certain mysterious properties with which they have been invested not only by tradition but even by scientific research.
We will not, however, venture to affirm that they are more wonderful or deserving of a higher place in the estimation of man than the beautiful and more transient flowers of vegetation. Both are indeed objects of our highest consideration.
The transparent diamonds always occur in crystalline forms, although they sometimes appear almost amorphous or even cylindrical or globular. Its primitive form, however, is the octahedron.
They are found generally in limited deposits, which are often as shallow and well defined as the gold fields, which are termed placers; and therefore we will also call the diamond fields “diamond placers.”