Dredging has been employed in mining these deposits, but does not appear to have been a success, and operations are now largely confined to native washings[[88]].
French Guiana
Platiniferous gold-bearing sands are found in the Aporuague River, the metal, according to an analysis by A. Danmer, having the following composition in percentages: platinum, 41·96; gold, 18·18; silver, 18·39; copper, 20·56[[89]].
WORLD MAP OF PLATINUM DEPOSITS
Map showing the platinum-bearing districts referred to in the Text.
(British Empire and Protectorates shaded.)
REFERENCES TO LITERATURE ON THE PLATINUM METALS
[1]. Lindgren, W.: “Platinum and Allied Metals,” U.S. Geol. Surv., Min. Res. of U.S., 1911.
[2]. Thomas and MacAlister: The Geology of Ore Deposits, London, 1909.