Mica.

Manufacturer and builder 11, 1881

While speculation in mica mining is rife, there are few mines that prove paying investments. Nothing is more common than mica deposits in some form, but nothing is more uncommon than to find a mine which will yield a good profitable return for the money invested. Nature has been very capricious regarding this mineral, and out of some two hundred mines is this country, it in not probable that over half a dozen approach anywhere near "bonanzas." Even suppose the mine to yield mica in sufficient quantity, there are several features in the business which tend to diminish plaits. In the first place, of the mica taken from the mine about 6 per cent is worthless; opaque mica is not a merchantable article, and must be thrown aside. Afterwards, when the mica is cut into required sizes, there occurs a shrinkage of front 40 to 60 per cent. The mica trade hinges on the stove business, for in stove doors does mica find its chief use. It has a very limited use for scientific purposes, electrical apparatus, compass cards, lanterns, etc. It is employed for battle lanterns on war ships, for the concussions incident to naval engagements would soon shatter glass. All these uses, however, are insignificant compared with its application to heating apparatus. Were not the production of mica limited to nature's stores, which she very sparingly doles out, there would have undoubtedly been new uses discovered for the mineral long before this.

New Hampshire and North Carolina furnish most of the mica required, though deposits exist supposed to be at least three hundred years old, was found. There has been much small mica thrown on the market in recent years, and prices of this kind have declined, but large mien, being scarce, maintains its price. The number of farmers in Maine, New Hampshire and Vermont who have discovered mica deposits on their estates, and who have seen prospective wealth therefrom, is legion, but the number who have really profited by their discoveries is very small.