Mining Tourmaline

Digging for tourmalines, at least in one locality, offers the fascination that, in some form, seems always present in the mineral industries. One of the earlier sources of supply of tourmalines was Burma, and an interesting description of some of the phases of the quest for tourmalines was written by Mr. C. S. George, deputy commissioner for the Ruby Mine District, Burma, for the London Tribune. Tourmaline, as found there, is in separate crystals in the interstices of granite rock, and men with no capital can mine here and do, in a desultory manner, on the chance of finding more or less valuable bits by digging down a distance of ten feet or less. This was the method of mining at the original ruby diggings at Kathe. The more modern method is that of sinking a vertical shaft four or five feet square. Custom allows the proprietor of the shaft to extend his workings underground anywhere to a radius of five fathoms from the centre of the shaft.

A writer—Mr. C. S. George referred to above—in the Jeweller's Circular Weekly states:

The vein is formed by a vein of white hard granite rock, in the interstices of which the tourmaline is found, at times adhering loosely to the rock, at others lying separate in the loose yellowish earth that is found with granite. When a vein is once found it is followed up as far as possible, subject to the five fathom limit. What, however, makes the mining so exciting and at the same time keeps the industry fluctuating is that the tourmaline crystals are found only intermittently in the vein. One may get several in the length of one yard, and then they will unaccountably cease. Directly one man strikes a vein yielding crystals every one who can commences digging along the line of the vein, but it is all a toss-up as to whether, when the vein is reached, there will be tourmaline therein. Adjoining shafts give absolutely different results, and it is calculated that at least two thirds of the shafts sunk yield nothing at all, while only an occasional one is at all rich.

Of the sixty-two shafts at the time of Mr. George's visit only three were yielding, and of these only one had traces of the best quality stone. The veins are fairly deep down, none having ever been reached at a lesser depth than nine fathoms, while an ordinary depth is forty or fifty cubits. When the "vein" takes a downward direction it is followed as far as possible, but that is rarely over about sixty cubits, for at that depth the foulness of the air puts the lamps out.

All the material dug out from the inside shaft is pulled up to the surface in small buckets, all worked by enormously long pivoted bamboos weighted with a counterpoise, and the tourmaline is sorted out of hand, the granitic fragments being piled in a wall around the mouth of the shaft.