More than a third of the world's production of silver comes from Mexico which outranks other leading producers such as United States, Canada and Peru.

For fine hollow-ware, flat-ware and jewelry, silversmiths employ "Sterling" silver, an alloy containing 92.5% by weight of pure silver, balance copper. The silver coinage of the United States is made of. "Coin Silver," an alloy containing 90% of pure silver and 10% copper.

Large amounts of silver of high purity are consumed in making the light-sensitive emulsion of photographic films and papers, and for . electroplating. Alloys rich in silver are used extensively for joining metal parts in the production of automobiles, home refrigerators and other machinery.

GOLD

Pure gold, one of the heavier elements, weighs 0.698 lb. or 201 dwt. per cu. in. Gold is a soft, ductile metal of yellow color, melting at 1945°F.

Over 40% of the world's production ismined in the Union of South Africa, the leading producer. Canada and the United

States are other important producers of gold.

Jewelry has been made of gold and gold alloys for thousands of years. The ancient jewelry was fashioned by hand from metal that often contained over 90% of pure gold.

The present practice is to manufacture jewelry of the so-called "karat golds," which are gold alloys having more strength and durability than pure gold. For 18K, 14K and 10K alloys, the nominal content of pure gold is respectively 75%, 58.5% and 41.7% by weight. In the karat system of marking, pure gold is designated as 24 karats; therefore a 14K mark indicates 14/24 (58.5%) of pure gold.

For karat golds made in U. S. A., the nominal and actual content of pure gold usually are almost identical. However, the marking laws permit the actual content to be less than the mark indicates, by .5k for unsoldered articles and by lK for soldered articles. Thus a soldered article marked 10K may contain as little as 9/24 or 37.5% of pure gold, measured by weight.

The karat golds are available in several colors described as yellow, red, pink, green and