Maine Mineral And Gem Museum

Rhyolite Drill Core

The Callahan Mining Corporation extracted copper and zinc ores from the volcanic rocks of the Castine Formation at the Harborside Mine from 1968 to 1972. This is a 48 inch-diameter core section that was drilled for a ventilation shaft.

Location: Harborside Mine, Brooksville, Hancock County

Gift of The Benenson Family