Home › Magic Stones and Electric Gems › Magic Stones and Electric Gems: Haberden

Magic Stones and Electric Gems: Haberden

Toward the middle of the eighteenth century Dr. Haberden, of London, confirmed the deductions of Lemery and the somewhat later experiments of the German physicist Aepinus, and the gay world of London took up the idea, causing the new stone to become a great favorite with the fashionable. One of Hogarth's inimitable designs depicts a spendthrift fop who has just been arrested while his attention was riveted on the strange phenomena shown by the tourmaline. In view of the important experiments made by Benjamin Franklin in the then almost unexplored field of electricity, it is easy to understand that the accounts of the newly-discovered electric properties of the tourmaline should have possessed considerable interest for him. This is testified to by a letter he addressed to Dr. William Haberden, June 7, 1759. Herein he expresses his thanks for two tourmalines his correspondent had sent him, and states that he is returning the smaller one. Of the electric phenomena he writes that he had heard some "ingenious gentlemen abroad" had denied the negative electricity displayed by one side of a tourmaline, but he believes the failure to observe could be explained by defective cutting of the specimens used, the positive and negative planes having perhaps been obliquely placed; to obviate this he suggests that the positive and negative sides should be accurately determined before the operation of cutting begins. The larger of the specimens sent by Dr. Haberden was retained by Franklin, who had it mounted on a pivot in a ring, so that either side could be turned outward at will. He notes as a curious circumstance that when he wore this ring, the natural heat of the finger sufficed to charge the stone, causing it to attract light bodies. Several of his experiments were made with a cork ball suspended by a thread, and he claims that the attractive force of the positive face was increased by coating it with gold-leaf attached to the stone by white of egg. This greater effect he supposed "to be occasioned by the united force of the different parts of the face collected and acting together through the metal." While the various corundum gems, ruby, sapphire, Oriental topaz, Oriental amethyst, etc., offer a remarkable instance of the many varieties of beautiful coloration observable in a practically identical substance, no single gemmineral can be said to equal tourmaline in this respect, more especially, however, in the combination of several colors sometimes disposed in bands, at other times in concentric circles in the same crystal. When to this we add its peculiar electric qualities, we may truly say that a fine tourmaline answers our idea of what a talismanic gem or a gem-amulet should be better than any other of the beautiful crystals with which bountiful nature has provided us. These most attractive stones are to be found in widely separated regions on the earth's surface, as fine examples have been discovered in the State of Minas Geraes, Brazil, and in our own land, in Maine and California especially. Where the color is homogeneous we may have the splendid red or rose-colored variety called rubellite, from its resemblance to the ruby, or the blue tourmaline gem named indicolite.

In times of old there was a belief that stones of various kinds would guard against the assaults of evil in the form of witchcraft, disease, and other disagreeable visitations. It was a warlike period in which peace was an unheard-of doctrine, and now that the idea of peace has become one of the ideals of present-day conditions, it is interesting to know that nature has furnished us with a stone at once beautiful, interesting, and illustrating the great fundamental principle of unity and peace.