 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
  |
||
 |
 |
Quality of: Diamond | Platinum | Gold | Manufacturing The Quality of Gold Rarely is pure gold ever used by the goldsmith for his wares. The pure metal is much too soft for either purpose. The required hardness is obtained by the mixture of some other metal of less value called alloy¹. In the case of gold the alloy used is either silver or copper or an admixture of both, and on the nature of the alloy the ultimate colour of the manufactured gold depends. The bright yellow of pure gold partakes of a greenish tinge when alloyed with silver, of a reddish hue when alloyed with copper, and of a paler yellow when alloyed with both silver and copper. Goldsmiths now mainly depend on Australia, South Africa and North America for their supplies of gold, and on North and South America for silver. It was, however, not always so, for in the past gold was found in considerable quantities in the British Isles. The ounce was originally divided into twenty-four parts called 'carats', and each carat into four grains. When gold is described as so many carats fine, what is meant is that the number of carats mentioned is pure gold: '18-carat gold' meaning a metal composed of 18 parts of pure gold and 6 parts alloy. 1 'Alloy' (from the French 'ą la loi' - according to law), the amount of base metal which may be added to pure gold or pure silver by permission of the law. |
|||
|
|
