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54 CHRYSOLITE FAMILY. found abundantly in the lavas of Vesuvius, Etna, Strom- boli, and other volcanoes. Geographic Situation. Europe.—In Scotland, it is imbedded in the basalt of Arthur’s Seat, and in the basalt, and other floetz- trap rocks around Edinburgh; in the basalt hills and cliffs of Fifeshire, and other floetz-trap districts in the mainland of Scotland; also in the Orkney islands, and those of Arran, Mull, Eigg, Canna, Rume, and Skye. In Ireland, it is not unfrequent in the floetz-trap rocks of the northern districts of that island. On the Conti nent, it is very widely distributed: thus, it occurs at Arendal in Norway, in Hessia, Saxon Erzgebirge, Bo hemia, Silesia, the Tyrol, Hungary, Transylvania, Italy, and France. Africa. In the basalt of the islands of St Helena, TenerifF, and Isle de Bourbon. America.—In the floetz-trap rocks of Mexico and the United States. Observations. 1. Distinctive Characters.—a. Between Augite and Basaltic Hornblende. Basaltic hornblende has always a velvet-black colour, augite most generally a green co lour ; the lustre of basaltic hornblende is vitreous, that of augite resinous; basaltic hornblende is softer than augite ; ^nd a simple chemical distinction may be added, basaltic hornblende is easily fusible before the blowpipe, augite difficultly —b. Between Augite and Schorl. The crystals of schorl have their lateral planes longitudinally streaked, those of augite are smooth ; the lustre of schorl is vitreous, that of augite resinous; it is harder than au-