THE DIAMOND. OO 



rule given is as follows : double the weight in caiats, ana 

 multiply the square of the product by £2. Thus a wrought 

 diamond weighing 1 carat, would be worth £8 ; one of 4 

 carats, £128 ; one of 10 carats, £800. Above 20 carats, 

 the prices rise much more rapidly. A flaw, however mi- 

 nute, or the slightest smokiness, diminishes very much the 

 value. The average price of rough diamonds, of first 

 quality, of 1 carat, is £2; of 2 carats, £8, since it loses 

 half its weight in cutting, and becomes then one of 1 carat 

 wrought. 



The rule just given is scarcely regarded in market, as 

 so much depends upon the purity of water. In different 

 countries, moreover, the standard of taste as regards dia- 

 monds is very different, the market in England demanding 

 the very first quality, while in other countries a somewhat 

 inferior kind satisfies the purchaser. 



The rose diamond is more valuable than a snow-white 

 diamond, owing to the great beauty of its color and its rarity. 

 The green diamond is much esteemed on account of its 

 color. The blue is prized only for its rarity, as the color is 

 seldom pure. The black diamond, which is uncommonly 

 rare and without beauty, is highly prized by collectors. The 

 brown, gray and yellow varieties are of much less value than 

 the pure white or limpid diamond. 



The diamond is cut by taking advantage of its cleavage, 

 and also by abrasion with its own powder and by friction 

 with another diamond. The flaws are first removed by 

 cleaving it; or else by sawing it with an iron wire, which is 

 covered with diamond powder — a tedious process, as the 

 wire is generally cut through after drawing it across five or 

 six times. After the portion containing flaws has thus been 

 cut off, the crystal is fixed to the end of a stick, in a strong 

 cement, leaving the part projecting which is to be cut ; and 

 another being prepared in the same manner, the two are 

 rubbed together till a facet is produced. By changing the 

 position, other facets are added in succession till the required 

 form is obtained. A circular plate of soft iron is then charged 

 with the powder produced by the abrasion, and this, by its 

 revolution, finally polishes the stone. To complete a single 

 facet often requires several hours. Diamonds were first cut 

 n Europe, in 1456, by Louis Berquen, a citizen of Bruges; 



How are diamonds rut ? 



