Silver

This stunning slab represents "old stock" high-grade silver from the historic O'Brien Mine in Coleman Township, one of the foundational operations of the Cobalt mining camp. The specimen consists predominantly of native silver within a dolostone matrix, showcasing the exceptional ore quality that the mine was known for.

The O'Brien Mine, discovered in 1903, holds a prominent place in Canadian mining history. It became one of the most significant producers of silver in the Cobalt camp and was the area's longest continuously operating mine. The mine's development included five shafts, the deepest extending to 345 feet, with over 16 miles of underground workings such as drifts, cross-cuts, and raises.

This specimen serves as a remarkable relic of the rich mining heritage of the Cobalt district, embodying the impressive productivity and engineering achievements of the early 20th century.