( 226* ) 



Thej were ever ready to assist me in my examination of the works, 

 and freely gave me all the necessary information respecting them. 



Having detailed the process of washing for diamonds, I proceed to 

 a general description of the situations in which they are found. The 

 flat pieces of ground on each side the river are equally rich throughout 

 their extent, and hence the officers are enabled to calculate the value 

 of an unworked place by comparison with the amount found on 

 working in the part adjoining. These known places are left in re- 

 serve, and trial is made of more uncertain grounds. The following 

 observation I often heard from the intendant : " That piece of 

 ground" (speaking of an unworked flat by the side of the river) " will 

 yield me ten thousand carats of diamonds whenever we shall be re- 

 quired to get them in the regular course of working, or when, on 

 any particular occasion, an order from Government arrives, demand- 

 ing an extraordinary and immediate supply." 



The substances accompanying diamonds, and considered good in- 

 dications of them, are bright bean-like iron ore, a slaty flint-like sub- 

 stance, approaching Lydian stone, of fine texture, black oxide of 

 iron in great quantities, rounded bits of blue quartz, yellow crystal, 

 and other materials entirely different from any thing known to be 

 produced in the adjacent mountains. Diamonds are by no means 

 peculiar to the beds of rivers or deep ravines; they have been found 

 in cavities and water-courses on the summits of the most lofty 

 mountains. 



I had some conversation with the officers respecting the matrix of 

 the diamond, not a vestige of which could I trace. They informed 

 me that they often found diamonds cemented in pudding-stone, ac- 

 companied with grains of gold, but that they always broke them out, 

 as they could not enter them in the treasury, or weigh them with 

 matter adhering to them. I obtained a mass of pudding-stone, ap- 

 parently of very recent formation, cemented by ferruginous matter 

 enveloping many grains of gold ; and likewise a few pounds weight 

 of the cascalhao in its unwashed state. 



