History · Geology
About Cobalt, Ontario
The historic Cobalt Camp in Cobalt, Ontario, Canada was one of the world’s great native silver districts and the type-quality source of arborescent native silver wires and crystallized erythrite “cobalt bloom”. Mining peaked 1903-1930, producing over 14,000 tons of silver.
Geology
The deposit is a vein-type Ag-Co-Ni-As system in Proterozoic Nipissing diabase and Huronian sediments. Native silver and Co-Ni arsenides crystallized in carbonate-rich vein fillings; erythrite formed as oxidation product.
Notable Minerals
Native silver (massive plates, dendritic foliated leaves, herringbone crystals — world’s most spectacular native silver), erythrite (pink-magenta acicular Co-arsenate “cobalt bloom”), acanthite, niccolite, smaltite, calcite (large rhombs), dolomite, arsenopyrite. Silver-on-calcite is the iconic combination.
Collector Notes
Cobalt silver wires are American mineralogical history. Old-stock 1910-1920s specimens command premium provenance pricing. Pair with Kongsberg (Norway) for the world’s native silver collector display.
Minerals Produced Here
- Acanthite (辉银矿)
- Arsenopyrite (毒砂矿)
- Calcite (方解石)
- Dolomite (白云石)
- Erythrite (钴华)
- Silver (Native) (自然银)
