Datolite

Unknown Owner

A beautiful reddish-brown sliced datolite nodule, this polished and very attractive. This is classic material for the species and mining district.The Knowlton Lode at the Caledonia Mine in Ontonagon County, Michigan, was part of an important copper mining operation on the Keweenaw Peninsula that worked native copper in amygdaloidal basalt of the Portage Lake Lava Series. The lode became well known among collectors for producing datolite, which occurs as nodules and botryoidal masses often with pale pink color and occasional native copper inclusions. The Caledonia Mine was developed in the mid 1800s and continued operations until it closed in 1870.