A considerable part of the gold product is used in gilding picture-frames, book-titles, sign-letters, porcelain, and ornamental brass work. Practically, all of this is lost, and in the United States alone the loss aggregates about fifteen million dollars yearly. The abrasion and unavoidable wear of gold coin is another great source of loss.
An enormous amount is used in the manufacture of jewelry, most of which is used over and over again. By far the greater part, however, is used as a commercial medium of exchange—that is, as coin. For this purpose its employment is wellnigh universal; and indeed this has been its chief use since the beginning of written history. Gold coin of the United States is 900 fine, that is, 900 parts of every thousand is pure gold; gold coin of Great Britain is 916-2/3 fine. In each case a small amount of silver, or silver and copper, is added to give the coin the requisite hardness. The coining of gold, and also other metals, is a government monopoly in every civilized country.
The fiat value of gold throughout the commercial world is the equivalent of $20.6718 per troy ounce of fine metal; an eagle weighs, therefore, 2580 grains. The real value, however, is reckoned by a different and a more accurate standard, namely, the labor of man, and this, the sporadic finds of placer gold excepted, has not changed much in two thousand years or more. The increased production has scarcely equalled the demand for the metal; moreover, the longer a mine is worked the greater becomes the expense of its operation. Improved processes for the extraction of gold have not created any surplus of gold; indeed, the supply is not equal to the demand; and this fact keeps the metal practically at a fixed value.
Silver.—Silver is about as widely diffused as is gold, but it is more plentiful. It is found sparingly in most of the older rocks and also in sea-water. It was used by the Greeks for coinage more than eight hundred years before the Christian era, and was known to the Jewish people in very early times. According to the writer of the Book of Kings (1 Kings x. 21), "It was nothing accounted of in the days of Solomon," but Tacitus declares that in ancient Germany silver was even more valuable than gold. The mines of Laureion (Laurium) gave the Greek state of Attica its chief power, and the failure of the mines marked the beginning of Athenian decline.
Silver is rarely found in a metallic state. For the greater part it occurs combined with chlorine ("horn silver"), or with sulphur ("silver glance"), or in combination with antimony and sulphur ("ruby ore"). The ranges of the western highland region of the American continent yield most of the present supply. The mines of Colorado, Montana, Utah, and Idaho produce about six-sevenths of the yield in the United States, which in 1900 was 74,500,000 ounces. In Europe the Hartz Mountains have been famous for silver for several centuries.
About four-fifths of the silver bullion is used in the arts, most of it being manufactured into ornaments or into table-service called "plate." A considerable amount is used in photography, certain silver salts, especially the chloride and the bromide, changing color by exposure to the light. The remaining part of the silver output is made into coin.
The ratio of silver and gold has fluctuated much in the history of civilization. In the United States the value of an ounce of fine silver is fixed at $1.2929, thereby making the ratio 16 to 1. The silver dollars, 900 fine, were coined on this basis, weighing 412.5 grains. With the tremendous output of the silver mines between 1870 and 1880 the price of silver fell to such an extent that, in time, most countries limited the amount of coinage or demonetized it altogether. In the United States the purchase of silver bullion for coinage has been practically suspended, and the silver purchased is bought at the bullion value—about fifty cents per troy ounce in 1900. In Japan the ratio has been officially fixed at 32 to 1.
Copper.—Copper is probably the oldest metal known that has been used in making tools. An alloy of copper and tin, hard enough to cut and dress stone, succeeded the use of flint and jade, and its employment became so general as to give the name "bronze" to the age following that characterized by the use of stone implements.
Copper is very widely distributed. It occurs in quantities that pay for mining in pretty nearly every country in the world. The rise of Egypt as a commercial power was due to the fact that the Egyptians controlled the world's trade in that metal, and it is highly probable that the conquests of Cyprus at various times were chiefly for the possession of the copper mines of Mount Olympus.
At the present time there are several great centres of production which yield most of the metal used. These are the Rocky Mountain region, including Mexico; the Lake Superior region of the United States; the Andean region, including Chile, Peru, Argentina, and Bolivia; the Iberian region, consisting of Spain and Portugal; and the Hartz Mountain region of Germany. In 1900 they produced about four hundred and fifty thousand tons, of which two hundred and eighty thousand were mined in the United States.