"Sure he would," agreed Jim, "but gold goes where it durn pleases, an' that's the only rule I know. O' course, every prospector has his own idees, same as he has for playin' poker, but he don't win any quicker because o' that. Leastways, not so far as I've seen.
"As for judgin' by the rock an' the color o' the soil, why, you can take your pick. Take San Diego County, Californy, where I've worked, the gold lies in schist, sometimes blue, green, or grey. In the Homestake, South Dakota, red looks good, a sort o' rotten quartz stained with iron. Black flint's a good sign in Colorado. Snow-white quartz is often lucky. Purple porphyry sometimes has veins that work up rich. An' I've seen gold come out o' pink sandstone, yellow sandstone, all shades o' granite, an' even coal!"
Clem turned an incredulous glance at Owens, but the mine-owner nodded agreement.
"Jim's right," he said, "color isn't any clue. Gold can be found in any kind of rock. So far as that goes, it shows up in strata of any geological age. There's gold everywhere. There isn't a range of hills in any country of the world which may not contain gold. There isn't a bed of sand or gravel that may not be auriferous. Even the sea beach, in places, has yielded fortunes. For that matter, there's gold in every bucket of water you dip up from the sea.
"But there's not much of it. Geologists have figured that there's about one cent's worth of gold to every ton of rock in the earth's crust, but it would take fourteen dollars a ton to handle it. There's about a hundredth of a cent's worth of gold in a ton of sea water, and it would cost about ten dollars a ton to get it out. Not much chance of getting rich that way, is there?"
"I should say not," declared Clem, with decision.
"But, as Jim has been pointing out, gold isn't scattered evenly all through the earth. In some places, it's moderately plentiful, in others it's scarce or entirely absent. Prospecting for gold, Clem, doesn't mean looking for a place where there is gold, but looking for a place where the proportion of gold to the soil or to the rock is high enough to give a profit in the working of it.
"It isn't always the place where the gold is most plentiful that gives the greatest profit, either. A low-grade ore, that is a rock containing only a small proportion of gold, may be worth a great deal if it is near the surface, if the rock is easily crushed, if it is near water-power, and if transportation is not too difficult.
"A high-grade ore, in which there is a large proportion of gold, may be worth a good deal less, if it is more difficult to work and less easy of access. The richest gold-field in the world, that of the Rand, in South Africa, which gives one-third of the total gold output of the world, is of an ore so poor that a forty-niner would have turned up his nose at it, and the machinery, even of thirty years ago, could have done nothing with it. Nearly all the big mines of to-day are winning wealth out of low-grade ore.
"Some of these days, Clem, I'll explain the geology of gold to you, and show you how it is that the mines which give the richest specimens are sometimes the poorest mines to work. But I'm breaking into Jim's story."