UNITED STATES, CANADA AND MEXICO	157
	develop as large crystals as those from the Tyrol, since they show the pleochrism beautifully, their color changing, as viewed in dif­ferent directions through the prism, from dark grass-green to a rich yellow-green.
	EPIDOTE
	Zoisite is a silicate of alumina containing from 2 to 9 per cent, of oxide of iron. Its quality, as found in the United States, has not been such as to adapt it for use as a gem. Some beauti­ful specimens of yellowish-brown and greenish-gray crystals have been found at the Ducktown, Tenn., Copper Mines. The rose-red or thulite variety has been found at Deshong's Quarry, Del­aware County, Pa., but this is not as handsome or as compact as the beautiful rose-red variety which occurs in considerable quanti­ties at Trondhjem, Norway, some of which has been used for ornamental purposes. No crystals of axinite have been found in this country of sufficient size to furnish gems. It has been observed near Beth­lehem, Pa., at Cold Spring, N. Y., and associated with essonite and idocrase at Phippsburg and Wales, Me. The first-named locality, discovered by Prof. Frederick Prime, Jr., is in North­ampton County, about three miles north of Bethlehem. Speci­mens from this place have been examined by Prof. Benjamin W.