WORKING DIAMOND MINES.

New Zealand Herald, Volume XVIII, Issue 5997, 5 February 1881, Page 7

WORKI NG DIAMOND MINES.

The sj-stem of of working the diamond miSSOJ is described by an operator as follows :—The ground being picked loose by natives and broken up, is hauled out of the mines iu tubs running on inclined wires; from these tubs it is transferred to a sifting cylinder, which removes the coarser stones, the remaining soil boing mixed with water and slowly stirred in a flat pan of circular form, by means of arms fitted with teeth, this pan varying from six to fifteen feet in diameter, according to the amount of work to be done. The effect of this is to leave the diamonds which are heaviest at the bottom ; the lighter soil escaping over the edge of the pan to be taken up by a dredger and trucked away." At the end of a day's work the contents of the circular pan are cleaned out and washed up in hand sieves, when, in turning over the seivcen the table, the diamonds can be at once seen from their brilliance, some being of most perfect octahedron shape, and as clear as crystal. The rough diamonds are almost invariably below ten carats in weight, the average being about the size of a pea ; indeed, in the Unit- j fontein mine a ten-carat stone is looked upon I as a curiosity, though specimens exceeding j 100 carats have on rare occasions been secured. The value of a stone depends entirely on its ' colour, shape and freedom from spots or Haws; those of faultless shape and perfect whiteness taking the precedence of all others. The diamonds exceeding twenty carats iu wei.ht i are mostly of various shades of yellow, alav fe e white diamond being a comparative rarity.