228 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



reported to have been found in other places have in many cases been placed there with the 

 object of swindling a credulous public. 



As an example of the almost incredible extent to which the public have been swindled 

 by false reports as to the occurrence of diamonds, an account of a supposed discovery in 

 the State of Arizona may be given. In the year 1870, a fabulously rich occurrence of 

 various precious stones, including the diamond, was reported to have been discovered 

 somewhere in the West. 80,000 carats of rubies and a single diamond weighing 108 carats, 

 said to form part of the find, were exhibited in a San Francisco bank. Shortly after this a 

 smaller lot of stones, said to be the result of a second search, were on view in this city, and 

 the attention of capitalists was soon enlisted. On May 10, 1872, a Bill in the interests of 

 the diamond-miners was passed by Congress, and an expedition for investigating the locality 

 was fitted out. After some trouble the locality was found, and in the course of a week the 

 members of the expedition had collected 1000 carats of diamonds and 6000 to 7000 carats 

 of rubies, and returned well pleased with their success. Another expedition failed to find 

 the place, and an investigation by the officers of the United States Geological Survey proved 

 the supposed discovery to be a gigantic swindle, the locality having been " salted." The 

 supposed rubies were in reality ordinary garnets, and although the smaller diamonds were 

 genuine the 108-carat stone was nothing but rock-crystal. It was ascertained that a 

 speculative American had imported a large number of rough Cape diamonds, and had 

 scattered them about the neighbourhood so plentifully that stray stones were found there 

 for some years afterwards. The initial outlay of the speculative American was amply 

 repaid by the three-quarters of a million dollars subscribed by Californian and other 

 capitalists. 



Diamonds are sought for very diligently in America ; it is not unusual for gold miners 

 and labourers engaged in the work of excavation to wear rings set with small, rough diamonds 

 for the purpose of familiarising themselves with the appearance of this stone in its rough 

 condition. In spite, however, of the alertness of persons engaged in such occupations, only 

 a small number of stones continue to be found, though it is always possible that future 

 discoveries of importance may be made. 



7. BRITISH GUIANA. 



In recent years diamonds have been found in another part of South America, about 

 2000 miles north-west of the famous Brazilian localities, namely, in the gold-washings on 

 the upper course of the River Mazaruni in British Guiana. The discovery was. made 

 accidentally in 1890 by Edward Gilkes, who, while prospecting for gold along the Putareng 

 creek, a tributary of the Mazaruni, found a few diamonds in the batea he was accustomed 

 to use for gold-washing. The locality is situated in latitude 6° 14' N. and longitude 

 60° 18' W., about 150 miles above the town of Bartica on the confluence of the Mazaruni 

 and Essequibo rivers. It is reached after a twelve to twenty days' journey, according to the 

 state of the river, which has many falls and rapids, from Georgetown. The exact spot is 

 situated about four miles from the Mazaruni, and is reached by a narrow trail across swampy 

 land and through tropical jungle, everything having to be carried on the heads of Indians. 



The rocks of the Mazaruni valley are largely gneisses and granite traversed by dykes of 

 diabase and other similar rocks. The diamond-workings at present under consideration are 

 situated on the side of a hill, and penetrate (1) 18 inches of pure, white quartz-sand, (2) 18 

 inches of yellowish, sandy clay, with fragments of quartz and portions of sand and gravel 

 cemented together by iron oxide, in which small diamonds are occasionally found, (3) 7 feet— 



