The processes of mining gold which still remains in its original home in the rocks are far more complicated. There is a vast amount of boring to be done into the flinty hearts of the mountains, with diamond-pointed drills and with blasting; and then the rock, which is dotted with the precious yellow flakes, has to be crushed between the steel jaws of great mills. Much of the gold that is mined, too, is so chemically changed that it does not look like gold at all, and requires special chemical processes to coax it out. In gold (and silver) mining mercury is one of the most important factors. It is the mineral sheriff, and swift to arrest any fugitive fleck of gold that may come in its way. The sluice boxes in extensive placer mines, and the “sheets” in stamp mills are all charged with quicksilver, which saves a vast amount of the finer gold dust that would be otherwise swept away by the current of water—for water is equally essential in both kinds of mining.
There is no such thing as pure gold, often as we hear the phrase. Nature’s own “virgin gold” is always alloyed with silver; and the very purest is but 98 or 97 per cent gold. California gold averages about the fineness of our American coin—90 per cent pure. As a general rule, the lighter the color the purer the gold. The beautiful red gold gets its color from a large alloy of copper.
It is an odd fact that the sea is full of gold. No doubt at the bottom of that stupendous basin which has received for all time the washings of all the world, there is an incalculable wealth of golden dust; but the strange ocean mine is not all so deep down as that. The sea water itself carries gold in solution—a grain of gold to every ton of water, as a famous chemist has shown.
Among the historical big nuggets found in various parts of the world, there have been some wonderful yellow lumps. In Cabarrus county, N. C., one was found in 1810 which weighed thirty-seven pounds Troy. In 1842 the gold fields of Zlatoust, in the Ural, gave a nugget of ninety-six pounds Troy. The Victoria (Australia) nugget weighed one hundred and forty-six pounds and three pennyweights, of which only six ounces was foreign rock; and the Ballarat (Australia) nugget was thirty-nine pounds heavier yet. The largest nugget ever found was also dug in Australia—the “Sarah Sands,” named for a far-off loved one. It reached the astonishing weight of two hundred and thirty-three pounds and four ounces Troy! I wonder what Miner Sands felt when he stuck his pick into that fortune in one lump!
The quality which makes gold commercially the most valuable of the metals is its docility. The cunning hammer of the smith can “teach” it almost anything. The more stubborn metals crumble after a certain point; but gold can be hammered into a sheet so infinitely fine that 282,000 of them, piled one upon the other, would be but an inch thick! And a flake of gold tiny as a pin-head can be drawn out, a finer thread than ever man spun, to a length of five hundred feet!
There is no end to the uses of gold. They broaden every day. In some one of its many forms our Yellow Slave helps us in almost every art and walk of life. It has become as indispensable as its red fellow-slave, fire—and like fire can be as bad a master as it should be a good servant.