COCCOLITE. 61 Chemical Character. It is very difficultly fusible before the blowpipe. Constituent Parts. Silica, 50.0 Lime, - 24.0 Magnesia, 10.0 Alumina, 1.5 Oxide of Iron, 7.0 Oxide of Manganese, 3.0 Loss, 4.5 100 Vauquelin. Geognostic Silvatmi. It occurs in mineral beds subordinate to the primitive trap formation, where it is associated with granular lime stone, garnet, and magnetic ironstone. Geographic Situation. It occurs at Arendal in Norway; in the iron mines of Hellsta and Assebj’o in Sudermannland; and in many places in Nericke, in Sweden. The mountain-green va riety is found at Barkas in Finland. It is mentioned as occurring in the Ilarzeburg Forest in the Hartz, in Lower Saxony; and also in Spain. Observations. 1. Distinctive Characters. a. Between Coccolite and Common Garnet: The internal lustre of common garnet is resinous, that of coccolite vitreous; the fracture of common garnet is uneven, that of coccolite is foliated ; common garnet scratches quartz, coccolite only glass: common