230 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



8. URAL MOUNTAINS. 



The discovery of diamonds in the Urals resulted from the famous expedition made in 

 1829 to this region by Alexander von Humboldt, with Gustav Rose and Ehrenberg, at the 

 desire of Czar Nicholas. In 1823, in his Essai giognostique sur le gisement des roches, 

 Humboldt had expressed an opinion, based on the similarity between the Brazilian and 

 Uralian gold- and platinum-bearing deposits, that diamonds very probably existed in the 

 Uralian deposits just as they were known to do in Brazil. This conclusion, which was 

 supported by the fact that the minerals associated with gold and platinum in the Urals and 

 in Brazil were practically identical, had been previously and independently expressed by 

 Professor Moritz von Engelhard t of Dorpat, who later investigated and reported on the first 

 diamond occurrence in the Urals. Humboldt was so convinced of the ti'uth of his opinion, 

 that on his departure he assured the Czarina that he would not again appear before her 

 Majesty unless he had some Russian diamonds to show. 



Throughout their whole journey the explorei-s spared no pains in their search for the 

 precious stones ; every gold-bearing sand they met with was subjected to microscopical 

 examination in order to detect the presence of diamond ; their efforts, however, were not 

 crowned with the success they deserved. 



Better fortune fell to the lot of Count Poller, who accompanied the expedition part of 

 the way and to whom Humboldt had communicated some of his own enthusiasm on the 

 subject. On leaving Humboldt's party, therefore, the Count set himself seriously to work in 

 the mining district of Bissersk (about latitude 58|° N.), in the gold-washings on the estates 

 of his wife, the Princess Shachovskoi. Here the first Uralian diamond, indeed the first 

 European diamond, was found on July 5, 1829. The exact locality was the small gold- washing 

 of Adolphskoi, near the larger washing of Krestovosvidshenskoi, twenty-five versts (seventeen 

 miles) to the north-east of Bissersk, and four versts (about three miles) from the mountain 

 ridge on the western or European slope of the Urals. It is situated in a side stream of the 

 Pakidenka, one of the head-streams of the Koiva, which flows into the Chussovaya, itself a 

 tributary of the Kama river. 



The muddy-looking gold-sand of the Adolphskoi washings contains, besides diamonds 

 and gold, a few grains of platinum, also quartz, limonite, magnetite, much iron-pyrites 

 (either bright yellow and unaltered or altered on the surface to limonite), chalcedony, 

 anatase, &e., and fragments of the neighbouring rocks. All these minerals and rock- 

 fragments have been derived from the mountain ridge which overhangs the stream, and 

 which is principally composed of a quartzose chloritic talc-schist, which has been suggested 

 to be identical with the Brazilian itacolumite, but which, according to the investigation of 

 G. Rose, in no way agrees with this. This chlorite-talc-schist contains subordinate beds of 

 haematite, grey limestone, and especially dolomite, coloured black by carbonaceous matter. 

 This dolomite immediately underlies the gold-sands of the Adolphskoi washings, and was 

 considered by von Engelhardt to be the original mother-rock of the diamond. Other 

 observers regard the chlorite-talc-schist as the mother-rock ; since diamonds have as yet 

 only been found loose in the sands and never embedded in rock, the point remains a 

 disputed one. 



Only about 150 diamonds have hitherto been found in the Adolphskoi gold- washings, 

 so that the discovery of this locality has not in any way affected the diamond market. The 

 stones are colourless to yellowish, perfectly transparent and very brilliant ; a few crystals^ 

 however, show dark brown or black enclosures ; their crystalline form is almost invariably 

 the rhombic dodecahedron, the faces of which are curved and nicked along the short 



