On Gems* 105 



tliem to wash the earth obtained : when well washed and 

 dried, thev sift it in a kind of open sieve, and search it well 

 for tlie diamonds it may contain. Tiiese people work also 

 naked, with inspectors over them. 



The diamonds from the river Gaoul and Succudan are 

 obtained by damming or stopping a part of the rivers, 

 which they empty of their water; then taking up the sand, 

 they sift it and search it for the diamonds. 



The province of Brasil, which produces diamonds, is si- 

 tuated inland between 2i2J- and 1(3 degrees of south latitude : 

 its circumference is near G70 leagues. This province is di- 

 vided into four districts. The diamonds are found chiefly 

 in the last, called Sero Dosrio, or Cold Mountain. The 

 whole of this province is rich in the ores of iron, antimony, 

 zinc, tin, silver, and gold. 



The mountains are the true matrix of the diamond ; but 

 as the work in the beds of rivers and on their banks is less 

 tedious, can be conducted on a larger scale, and affords 

 larger diamonds, they abandoned the mountain, and formed 

 great establishments in the river of Toucanbnneu, which 

 ilows through the valley, and is near ninety leagues ia 

 length. It was found, on examination and digging, that 

 the whole surface of the ground immediately beneath the 

 vegetable stratum contained more or less of diamonds dis- 

 seminated and attached to a matrix, ferruginous and com- 

 pact in various degrees, but never in veins. 



These works are not carried on by the Portuguese go- 

 vernment, but are farmed to certain individuals, who are 

 bound bv contract not to employ above a stipulated number 

 of slaves upon these districts, as before this condition the 

 quantity of diamonds brought into the market considerably 

 lowered their value. 



In the choice of roygh diamonds great care should be 

 taken in regard to their colour, their being free from ex- 

 traneous matter, and their shape. 



The most perfect are crystallme, and resembling a drop 

 of clear spring water, in the middle of which you will per- 

 ceive a strong liflht playing with a great deal of spirit. If 

 the coat l)e !im(joth and bright, with a little tincture of green 

 in it, it is not tlie worse, and seldom proves bad : but if 

 there be a mixture of yellow witli green, then beware of it ; 

 it is a soft greasy stone, and will prove bad. 



If a stone has a rough coat tl)at you can hardly see 



through it, and the coat be white, and look as if it was 



rough by art, and clear of flaws or vein;, and no blemish 



N il cast 



