Silver

An excellent high-grade sample, sawn on one side and left rough on the other, displaying striking dendritic “herringbone” native silver intricately intergrown with nickel and cobalt arsenides. The sawn surface reveals the complex branching patterns of native silver typical of rich Cobalt–Gowganda ore, while the rough reverse preserves the natural vein texture. This is a particularly vivid and classic example of Ontario’s famed silver mineralization style.

The specimen originates from the Siscoe O’Brien Mine, also known historically as the Miller Lake O’Brien Mine, one of the premier producers in the Gowganda–Cobalt silver district. The deposit was discovered in 1908, acquired by the Miller Lake Company in 1909, and later by Siscoe Mines Limited in 1945. By 1962, mine workings had extended to a depth of 1,300 feet (as reported in Precambrian magazine, June 1962 issue).

Over its productive life, up to 1965, the Siscoe O’Brien Mine yielded an astounding 36,830,000 ounces of silver and 786,000 pounds of cobalt, making it one of the richest and most productive mines in the entire Cobalt–Gowganda camp.

A superb, high-grade historical specimen exemplifying the beautiful herringbone silver textures and mineral associations that define this classic Ontario silver district.