an outcrop of hard blue schist. Where the sandy covering is removed, a deposit of tufaceous nodular limestone is exposed.
Crossing the Vaal River at the Griqua mission-station of Backhouse, the author entered the true diamond-district. At Nicholson's farm, about six miles up the river, he observed the outcrop of a hard conglomerate, sometimes assuming the aspect of a breccia, composed of angular and rounded pebbles and blocks of quartz, jasper, &c. of all sizes to upwards of a foot in diameter. Overlying this was a highly ferruginous soil containing numerous pebbles of quartz, jasper, iron ore, &c, in which, the author was informed, several diamonds had been found.
From Backhouse the author pushed on to Likatlong, about sixty miles further north. On the road along the banks of the Vaal River he occasionally observed schistose rocks, and also a great deal of unstratified limestone, containing quartz and other pebbles, in which diamonds were said to have been found with limestone adhering to them. Beneath this limestone, when denuded away, a ferruginous clay, the same as above described, makes its appearance, and is searched by the natives for diamonds. The author considers that the number of diamonds found at Likatlong had been greatly exaggerated. He states that the diamonds were everywhere obtained from the ferruginous soil, and that the spots which had been searched were always near the river, and, as far as he observed, only on the right bank, where the level of the country for some distance from the river is lower than on the opposite side. He considers that the finding of diamonds on this side only is due to the absence of the great deposit of sand which raises the country on the opposite bank to a much higher level.
Discussion.
Prof. Tennant stated that he had lately seen as many as 500 diamonds from the South-African fields in the possession of one person, some weighing as much as 50 carats. He had seen another fragment of a stone which must have originally been at least as large as the Koh-i-noor.
December 21, 1870.
Valentine D. Colchester, Esq., 4 Buckland Villas, Belsize Park, N.W. ; H. J. Heighton, Esq., Gold Street, Kettering ; Thomas Hawksley, Esq., 30 Great George Street, Westminster ; Frank Rutley, Esq., of the Geological Survey of England, Jermyn Street ; Isaac Roberts, Esq., 26 Bock Park, Rockferry, Cheshire ; Richard Glascott Symes, Esq., of the Geological Survey of Ireland, of Victoria Terrace, Ballina, County Mayo, and 14 Hume Street, Dublin ; and Daniel Pidgeon, Esq., F.R.M.S., Banbury, were elected Fellows of the Society.
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