RADIATED CORNEOUS SILVER-ORE. Geognostic and Geographic Situations. It occurs in small veins, along with native silver, quartz, and heavy-spar, in gneiss or clay-slate. It has hitherto been found only in South America. ' Third Subspecies. Common Corneous Silver-Qrc. Gemeines Ilornerz, Karslcn. Id. Karslcn, in Magazin dcr Gcsellsphaft der Naturforschender Freiiude zu Berlin, b. i. s. 158. External Characters. Its colours are pearl-grey, and violet-blue; rarely olive- green and leek-green. By the action of the weather, it acquires a brown, and more rarely a black colour. It occurs massive, disseminated; and frequently crys tallised in the following figures : 1. Cube. 2. Cube truncated on the angles. 3. Octahedron. 4. Single four-sided prism. The crystals are generally small and very small, and are occasionally aggregated in rows, or in a scalar-like form. The very minute crystals form small flakes. The external surface is smooth. Externally the lustre is shining or splendent; inter nally glimmering, and often dull. The fracture is fine earthy. The fragments are indeterminate angular, and ratlier sharp-edged.