DIAMOND: OCCURRENCE IN SOUTH AFRICA 213 



1882-4. 1887. 



s. d. s. d. 



Eiver stones ... . 54 11 46 7 per carat 



Du Toit's Pan mine . 28 1 24 3 „ „ 



Bultfontein mine . . 210 17 11 „ „ 



De Beer's mine .... 20 11 17 5 „ „ 



Kimberley mine . . . 19 2 17 2 „ , 



These four mines yield, on an average, respectively, 077, 1-05, 3-15, and i'BS carats of 

 diamonds per cubic metre of " blue ground," so that the stones found in mines of which the 

 yield is poor, surpass in quality those found in richer mines. 



In the Jagersfontein mine, as has been already mentioned, are found the whitest, 

 largest, and most transparent of Cape diamonds, some of which approach, or even equal, 

 the beautiful blue-white Brazilian and Indian stones which are so highly prized. The 

 abundance of white stones in this mine is sometimes thought to be connected with the 

 complete absence of iron-pyrites, which is found everywhere else and has been supposed 

 to be the cause of the yellow colour of Cape diamonds. The beauty of these white stones 

 IS unfortunately, however, often impaired by the presence of spots and blemishes of 

 various kinds ; moreover, in addition to regularly and symmetrically developed crystals, 

 irregular intergrowths are not infrequently met with, so that a considerable proportion of 

 stones from this mine are unsuitable for cutting and have to be discarded. TTie stones 

 found here which are free from faults are of singular beauty ; they are comparable to the 

 diamonds of Bagagem in Brazil and command the very highest price. 



It has not hitherto been mentioned that the Kimberley and De Beer's diamonds are 

 supposed to be less hard than stones from Du Toit's Pan and Jagersfontein mines and from 

 the river diggings. 



The whole of the South African diamond trade centres round Kimberley. The 

 stones usually change hands in large lots and are often placed on the market directly 

 they come from the washing machinery. In other cases they are first sorted into parcels 

 containing various qualities ; this process offers great scope to the skill and discretion 

 of the diamond merchant, for the amount obtained for a lot of stones depends largely on 

 the arrangement of the stones of different size, quality, colour, &c., into parcels. 



Various trade names for different kinds and qualities of diamonds have been evolved 

 side by side with the development of the traffic in these stones. Only about four such 

 terms were originally in use ; a much greater number are at present in existence, and the 

 significance of some of the most important will now be given below. 



Crystals ov'Glassies are white, or nearly white, perfect octahedra. 



Round stones are crystals with curved faces ; these are sub-divided according to colour 

 into Cape white, first by-water, and second by-water. 



Yellow clean stones is a term which includes all yellow stones, these being grouped 

 according to their shade of colour into off-coloured (the lightest shade), light yellow, yellow, 

 and dark yellow. 



MSU is a term applied to crystals varying from white to yellow (by-water) and often 

 also to brown, weighing on an average not more than 1^ to If carats. The term " small 

 mele " is applied to similar stones as small as -^ carat. All stones characterised by this 

 term are round or glassies, never broken fragments. 



Cleavage is the term applied to crystals containing spots, to twinned crystals, and to 

 others which need to be cleaved before they can be cut ; thus the term " black cleavage " is 

 applied to stones which, in the rough condition, appear much speckled, but which, after 



