CHAPTER IV.
PROSPECTING FOR DIAMONDS, GOLD, SILVER, COPPER, LEAD AND IRON.
MINERAL RICHES, HOW DISCOVERED—INDICATIONS—SEARCHING FOR DIAMONDS, AND HOW TO DISTINGUISH THEM—PAYING LOCALITIES OF GOLD—“FOOL’S GOLD”—PROSPECTING FOR SILVER AND COPPER—WHERE TO LOOK FOR LEAD AND IRON.
THE mineral riches of a country are frequently discovered by attentively observing the fragments brought down by the action of water from the hills into the valleys; and on tracing these to their several sources, the veins from which they were originally detached, are in many instances found. Water also acts in another way a very important part in the discovery of mineral veins, as by closely examining the faces of the different gullies and ravines, which intersect a country, a ready means is afforded of ascertaining whether its strata are traversed by metalliferous deposits; and, therefore, in exploring with a view to its mineral productions, no opportunity should be lost of observing the various sections thus naturally laid bare.
When fragments of an ore are found on a hill-side, it is very evident that the vein must lie higher up. If the vein is horizontal and the fragments are found on the top of the hill, there is no probability of finding much if any of the vein, for generally it has been washed away. Ore-veins, however, are almost always nearly vertical; so that boring is of little use, as it might pass by the richest vein, or, striking it lengthwise, give a too favorable result.
As heavy minerals do not drift far, metals are always found near their source.
Horizontal beds can be worked at the least cost.
Pockets and nodules, or any detached masses of minerals, are soon exhausted. Veins, lodes and beds are most valuable.
Boring a three-inch hole, which costs about $1 a foot, is a good method of testing a mineral vein or bed which lies more or less horizontally. A shaft may be sunk in sandstone for from $6 to $3 per cubic yard; in slate and gravel, at from $2 to $1.
The existence of mineral springs, and the rapid melting of the snow in any locality, are no indications of ores.