The Caledonia Mine is the only Michigan copper mine I know of that's still active, mainly for purpose of specimen collecting. Copper and silver specimens had been found by the people on the guided collecting tours during the Keeweenaw Week in August. The mine is one of several mines best known for the colored datolites and they're usually colored with brownish red being the typical color. Occasionally, the datolites in other colors like blood red, orange, peach orange, and pink and those with epidote inclusions have been found. Some datolites are found in their vein forms usually with episode, calcite and copper. Some are found in seams filling in the mudslide cracks in one of those big sloping mining rooms and even there are some datolites hidden in the mine piles outside the adit. The mine is currently owned by Red Metal Retreat company (Whitman's no longer an owner). Kowlton Mine is a "Next Door"  to the Caledonia Mine and had produced some similar datolite specimens.