All About Tourmaline: Composition, Color, and Mining Locations

Brilliancy

Tourmaline is like beryl, a mineral which is in itself of great interest, especially to scientists, and one which in smaller crystals sometimes attains such beauty of coloring and brilliancy as to become of rare charm as a gem.

Its Composition

Tourmaline has always puzzled scientific authorities in determining its composition, and in lack of a concise or authoritative definition of the chemicals composing it, we will quote the following description of its composition given by Ruskin, in his "Ethics of the Dust": "A little of everything, there's always flint and clay and magnesia in it; and the black is iron according to its fancy; and there's boracic acid, if you know what that is, and if you don't, I cannot tell you today, and it doesn't signify, and there's potash and soda; and on the whole, the chemistry of it is more like a medieval doctor's prescription than the making of a respectable mineral."

As we noted at first, tourmaline as a mineral is quite distinct from its rarer gem species.

Its Colors

As a mineral it occurs in an opaque form, colored either black or brown, and is quite common as a rock-forming mineral, resembling somewhat in its occurrence in this form, horn-blend. These crystals often possess strange and beautiful qualities, notably that of having a strong dichroism, that is, the same crystals often have different colors, being at one end red and at the other end green; or, on the other hand, the crystal may show a blue center, then a colorless zone, and then one red and one green, and furthermore the crystal will always show two different colors according as it is viewed from one angle or another. The beauty of these changing colors is often very striking, and is the chief cause which has led the tourmaline to be widely appreciated as a gem.

In the cutting of the gem skill is necessary in order to so cut the specimen that it will exhibit its most beautiful color. The most valued colors are, as a rule, dark red, sometimes almost approaching that of the ruby, and dark green shading to blue or yellow.

Tourmaline Mines

One of the chief localities for the mining of the gem tourmaline is Paris, Maine. The discovery of this source was mainly accidental. Two boys of the neighborhood, Elisha L. Hamlin and Ezekiel Holmes, had for some time been interested in the study of the minerals which were of frequent occurrence in the fields about their homes. One day in the fall of 1820, after hunting some time for specimens, they were attracted by the gleam of something green at the roots of a tree. They eagerly secured the mineral, and found it to be a beautiful green tourmaline. However, it was late in the day and their explorations could not go further. Then chance further delayed the discovery of more of the beautiful crystals, for that night it snowed heavily, and no further work could be done in the frozen ground until the following spring. But with the first thaw the boys worked with great interest, and soon secured many fine gems. Since that time the locality has been extensively worked, and some of the gems taken from it have found places in the crowns of kings. Ten years ago it was estimated that $50,000 worth of tourmalines had been taken from this one spot.

Other localities for mining tourmalines are California, which furnishes in particular the red tourmaline, Brazil, Siberia, and Ceylon.