The occurrence of cobalt and nickel in the Silver Summit Mine, Coeur d'Alene district, Idaho

Cobalt and nickel of possible commercial interest have been discovered in the Silver Summit mine, Coeur d'Alene district, Idaho. Assay data indicate that an ore shoot contained about 0.40 percent cobalt and about 1.0 percent nickel in addition to the copper and rich silver ores. The cobalt-nickel mineral gersdorffite occurs in tetrahedrite-siderite veins. Gersdorffite is widespread in small amounts and appears to have been the first of the "ore shoot" minerals. The known occurrence of either cobalt bloom or gersdorffite in other properties of the Coeur d'Alene district Silver Belt suggests that other ore shoots may exist that contain commercial quantities of cobalt and nickel.