Prof. T. Rupert Jones — Diamond Fields of S. Africa. 55 



ments of chalcedony (agate and carnelian), with both rolled and 

 fresh crystals of quartz, and with much broken garnet and peridot. 

 A rusty coating of iron-oxide frequently obtains. Basalt, con- 

 glomerate, and sandstone, are among the coarser debris of the valley,^ 

 which is in some places "strewn with fragments of rock" (Cooper). 

 The diamonds are found in the gravel and in the sandy soil above 

 it ; and occasionally in the tufa here and there associated with the 

 gravel. The gravel or shingle occurs not only on the flats, but on 

 the hills and hillocks called "kopjes" (over 100 feet high). Some 

 at least of these seem to be protrusions of basalt, or outliers of 

 strata and dykes, of limited extent, with rifts (" kloofs") and hollows 

 on them. They are coated with sand and gravel, and the latter is 

 said to be particularly diamantiferous.^ 



Mr. Gilfillan, in the "Grahamstown Journal," July, 1870, states 

 that, "from the fact of the stratification being horizontal, and the 

 diamonds being exposed after heavy rains, and so many of them 

 having been found at intervals over a large surface (along the course 

 of the Vaal Eiver), and the surface having very little incline, I 

 came to the conclusion that the South- African diamond deposits 

 must extend over an immense tract of country, more or less imme- 

 diately at the surface, along the valley of the Vaal, and that where 

 the appearances are favourable, such as spots where there is little or 

 no vegetation, with quantities of pebbles of quartz variously coloured 

 (green and rose-coloured more particularly), and black and red and 

 ribbon jaspers, and rolled fragments of iron-ore, scattered over 

 the surface on a ferruginous soil, with conglomerate rock in the 

 vicinity, diamonds will be found both on the surface and a few 

 inches below it." 



Opportunities of examining parcels of the Vaal Eiver gravel 

 (mostly sorted) have been afforded me by Messrs. Atherstone, Ochs, 

 Grey, and others ; and Prof. Tennant has kindly aided me in draw- 

 ing up the following list of minerals from these diamond gravels, 

 both by adding from his own parcels, and by determining some that 

 were doubtful : — Chalcedony, Agate, red and white Carnelian, 

 Mochastone, Semiopal ; subangular and rounded. Quartz, pellucid, 

 smoky, milky, opaque ; both perfect and waterworn crystals. Ame- 

 thyst. Jasper and Lydite, waterworn. Calcite, fragments. Selenite, 

 crystals. Garnet (Pyrope) and Cinnamonstone :^ fragments of garnet 

 very plentiful, perfect crystals rare. Chlorite. Natrolite and Meso- 

 type, crystals and fragments. Olivine (Peridot), fragments plentiful. 

 Diopside, fragments. Tourmaline, perfect and broken. Hepatic Py- 



^ Dr. J. Shaw writes of the materials of the alluvium thus : — " The pebbles of sand- 

 stone, quartzite, crystalline sandstone, granite, clayslate, agate, tourmaline, iron- 

 pyrites, garnet, garnet-spinel [?], etc., which compose this alluvium, are all roundedly 

 polished and waterworn, and are imbedded at Klipdrift in a brownish fatty earth." — 

 JSTatwe, Nov. 3, 1870. 



2 All philologists must protest against the mongrel word " diamondiferous," 

 partly English and partly Latin, that the Colonists have adopted instead of " diamond- 

 bearing" or " diamantiferous." 



3 Some of these have been quoted as " Eubies." 



