Page:Popular Science Monthly Volume 4.djvu/471

Rh by any collection of corundum in the known cabinets of Europe—for from no other locality have such specimens been found, excepting in the perfect gems from Ceylon and Burmah.

We now come to the most interesting feature of the mine. It was natural that, with so much of purity in the amorphous mineral, and perfection and beauty in the crystals found with it, Colonel Jenks should conclude that there might be gems in the mine. But from no quarter but his own observations did he get any encouragement in this direction. The best English authority on gems and their localities, Prof. King, of Trinity College, Cambridge, says: "The corundum gems have never been found in place, but always in the alluvial or sands of the rivers." After eight years of residence in Ceylon, the source from which the best sapphires of the world have come from an early period, and much acquaintance with the best gem-localities of the island, Sir Samuel Baker remarks: "The sapphires were created in the peculiar secondary formation, where they are always found, which is composed of water-worn pebbles, in a conglomerate of blue and white clay, buried ten to twenty feet beneath the surface of the valleys," etc. This was the opinion of Buffon, and other eminent scholars. The ruby localities of Bactria, visited by Sir Alexander Burnes, are said by him to be of similar character. Sir James Tennent, in his elaborate work upon Ceylon, expresses similar views, yet ventures the opinion, from a survey of the whole subject, that gems might be found in place in the island. He says, in confirmation of this view, that he saw in one of the mountain-ranges "a stratum of gray granite, with iron pyrites and molybdena, which contained great quantities of very small rubies." Whether he ascertained the nature of the gems he calls rubies by analysis, or only from casual observation, he does not say; but garnets of great beauty so often occur in such a matrix that it would not be safe to rely on those stones he saw—unless analyzed—as the ruby corundum. Seeking information from a later, and perhaps we are justified in saying, on this matter, the most eminent authority, that of Dr. J. Lawrence Smith, of Kentucky, he says, in substance: "The gems of corundum cannot be expected to appear where the amorphous masses of the mineral abound, and, vice versa, that corundum, for commerce, will not be found with the precious gems," etc., his conclusion being based upon "the diverse composition of the two forms of the mineral, shown by analysis, and which would require for their formation different geological and mineralogical conditions, etc.

Not dismayed by this array of scientific opinion and experience, however, Colonel Jenks made careful examination of the material as it came from the miners' hands, and the results led him to give them special instructions as to the nature of their operations. As the geodes in the formation of silica have been found to contain the finest quartz crystals, he hoped to find in the mine something of the same character, of alumina. He was rewarded by one or more large pockets of geodes