268 



South Africa 

 is a gemmer. 



DISCOVERY 



Every native who owns a small plot 

 He works at gemming during the dry 

 season when he has little other work to do. and he looks 

 upon gem-recovery as a pastime which is possibly 

 remunerative. 



How did the Gems come There ? 



The geology of the gem districts of Ceylon is not of a 

 complex'nature. The whole island may be taken to be 

 of igneous origin. Granite and gneiss outcrop and 

 protrude everjnvhere, showing evidence of some huge 

 force that must once have piled the mass of rock to 

 an enormous height, very much higher than the 

 present surface. The gems, no doubt, may have 

 been in situ originally, but I have never seen or heard 



i.e. on the top or steep side of the hiUs — but a few are 

 found in the beds of mountain streams and natural 

 rock-riffles or depressions. The natural inference would 

 be that the gems, being of greater specific gravity, 

 would have remained more or less near the spot where 

 they were released ; but I am inclined to think that, 

 where a gem was encased in a piece of rock, it was 

 carried away to the lower level, and there washed and 

 rolled about imtil disintegration took place which 

 released it. Those that were freed at the higher level 

 became encased in the alumina-mud, or clay, or 

 kaoline, which gave the mass sufficient buoyancy to be 

 deposited in the lower gutters. These two processes 

 would explain the fact that gems are seldom found at 

 their spot of origin. 



Fig. I.— cutting 



of a gem being found embedded in rock. The only 

 instance which leads one to suppose that the gems were 

 once in situ is that garnetiferous granite is found in 

 quantities. On the cooling of the igneous mass, 

 fissures and cracks and the lamination of the rock sur- 

 face took place, and during the thousands of years of 

 denudation and weathering, hundreds of feet in thick- 

 ness must have been washed away to the lower vallej'S 

 and into the huge fissures. The rock-debris became 

 further decomposed and now forms the present surface ; 

 such debris is termed "latterite deposit," and provides 

 the soil that now produces tea and rubber. Where 

 the rock-debris has fallen down to a still lower level 

 it has become a much more decomposed latterite, and 

 is heavily charged with kaoline which no doubt came 

 from decomposition of the felspar in the granite. 

 There are very few gems found in the high elevations — 



I.l.^niNG GEMS. 



Scooping, Washing, Vanning 



As we have seen, the lower gem deposits are of a 

 very decomposed nature, being at the present day 

 invariabh^ under water, sometimes at great depth. 

 The gemmer in consequence only works during the dry 

 season, when the water is low, so that he can scoop 

 up the wash with a basket or old pot or a coconut 

 shell ; this is a very tedious and unreliable method, 

 but I have never seen any more modern method used. 

 I saw a case where the gemmer was confident that a 

 very^fine gem existed on his plot in about lo ft. of water, 

 and he dived down with a coconut shell for the precious 

 stone ; he had worked his gem plot on this system, 

 he said, for some years, and still hoped one day to get 

 the gem. The total amount of ground, hand-dredged 

 and brought to surface by this primitive method, was 

 about I J tons in three years. 



