UNITED STATES, CANADA AND MEXICO	151
	gray. Masses through which the pink and ruby corundum occur disseminated, are exceedingly beautiful. The mineral is hard enough to admit of a fine polish and is worthy of attention as an ornamental or decorative stone. Diopside, a variety of pyroxene, is found in the township of De Kalb, St. Lawrence County, N. Y., as short, stout, oily-green crystals, in color resembling the crystals from Piedmont, Ala. Parts in these have been found sufficiently large and clear to be cut into gems weighing from 6 to 8 carats each, and recently crystals have been obtained which in size and perfection rival any found in the world ; some of these will furnish gems of 12 to 15 carats each. This is the only known locality in the United
	DIOPSIDE
	States where this gem is found. At Richville, in the township of De Kalb, some very large crystals were found in 1884, several of which were over 3 inches long and 1 inch thick, with clear spots of gem material giving promise of cut gems weighing 20 to 30 carats each. The crystals generally averaged an inch in length. Associated with the garnets of Fort Defiance, Ariz., Gallup, N. M., and other localities in that part of the country, and in the detritus resulting from the decomposition of the peridotite in Elliott County, Ky., small pieces of almost emerald-green diopside are found, evidently a chromium diop­side similar to that found with South African diamonds. They are generally too small to afford gems of any value, but a few pieces have been found that are of sufficient size for very small gems. Rhodonite, a silicate of manganese, has been found in an extensive bed at Blue Hill Bay, Me., on Osgood's Farm, Mass., and in the neighboring towns; in Warwick, Mass.; in Irasburgh