454 THE POPULAR SCIENCE MONTHLY. 



large price was paid for mountain-land, at a site where the mineral 

 had been found on the surface in considerable quantities. A canal 

 was cut from a mountain near, that furnished hydraulic power ; a gang 

 of a dozen mountaineers were engaged as miners, and ground was first 

 broken in the search for corundum in position. There being no pre- 

 cedent or guide in mining for corundum, experience was the teacher, 

 and a dear one, for nearly a year of energetic and toilsome explora- 

 tion. The question to be solved was, whether the mineral in any 

 quantity lay beneath the surface, upon which, all former supplies had 

 been gathered ; and, if so, whether it would show itself in bowlders, 

 segregated masses, pockets, or true veins. The country rock is gran- 

 ite and gneiss ; the spur or ridge, where the mineral showed itself, a 

 trap of chromiferous serpentine, or chrysolite formation. The strata 

 developed is chrysolite rock, mixed with anthophyllite — a layer of 

 micaceous rock — a seam of chalcedony — a stratum of chlorite, of the 

 variety ripidolite, and a gangue of the same, which proves to be the 

 usual matrix of the corundum. Eight months of hard labor settled 

 the question that corundum was there in immense quantity, and that 

 it would be found in veins varying, as is usual in other minerals, from 

 a few inches to several feet in width. These should be termed, what 

 they are, embedded veins, between hanging and foot walls of chryso- 

 lite, the gangue being of various minerals — generally, however, of 

 ripidolite, as stated ; but sometimes that mineral running into mica 

 schist, talc, spinel, jefferesite, and feldspar. In one of these veins, in a 

 pocket of jefferesite — a golden-yellow mica — there was found much the 

 largest and finest crystal of corundum known, of a fine sapphire and 

 ruby color, weighing 312 pounds, and now the property of Prof. Shep- 

 ard, of Amherst College. This unique specimen would undoubtedly 

 command one thousand dollars, were it for sale, various collectors of 

 Europe being anxious for its possession. Corundum from this mine 

 proves to be of excellent quality. Taking sapphire as the standard at 

 100, the product of the mine has a power of from 90 to 97 as an abra- 

 sive, while that of the best emery, the Naxos, numbers from 40 to 57. 

 The veins, five of which have been opened, run northeast and south- 

 west, dip under at an angle of 45°, and are, at the deepest point 

 reached, seven to ten feet wide. There is also remarkable association 

 of other interesting minerals of tourmaline, spinel, zerkon, etc., while 

 the corundum itself shows almost every shade of color from white to 

 black. It is also remarkable that the mine contains all the varieties 

 in color, texture, and crystallization, found in the aggregate corundum 

 localities of the globe. Association of two colors in the same crystal 

 is spoken of by the best writers as a somewhat rare matter, even in 

 Ceylon. One crystal was shown us from this mine, weighing two 

 pounds, with blue, ruby, pink, yellow, and green colors of great brill- 

 iancy and transparency ; and a small hand-collection, which con- 

 tained a variety in form, perfection, and purity of color, not equaled 



