Em´ery

(formerly emeril , from O. Fr. emeril ; Gr. smir is , emery), an impure variety of corundum, of blackish or bluish-grey colour, chiefly found in shapele ma es and mixed with other minerals. It contains about 82 per cent of alumina, and a small portion of iron; is very hard; is practically infusible, and is not attacked by acids. The best emery is brought from the Levant, chiefly from the Island of Naxos. It is employed in cutting and polishing precious stones; in smoothing the surface of the finer kinds of lenses preparatory to their being polished; in the polishing of marble; by cutlers, locksmiths, glaziers, and other artisans. For all these purposes it is pulverized in large iron mortars or in steel mills, and the powder, which is rough and sharp, is carefully washed and sifted into eight or ten different degrees of finene . Emery-paper and emery-cloth are made by laying a thin coat of glue upon the fabric, and dusting the emery from a sieve of the required size.