Locality: Upper Peninsula, Michigan

Mohs: 2.5 to 3

These shiny nuggets of pure, all-natural copper were mined from Michigan’s Keweenaw Peninsula. While we use copper for all kinds of industrial purposes today, we’re hardly the first group of people to find this metal useful.

There’s a fascinating cultural story set in Michigan and starring both a mysterious Indigenous group of people, and their love of copper. This group is referred to as the Old Copper Culture, and as the name suggests, they were working with a lot of the stuff. Michigan is home to the largest deposit of pure copper in the world.

But strangely enough, the Old Copper Culture stopped using copper for tools about 3,000 years ago, opting instead to go back to using stone tools, and only using copper for ornamental purposes. Turns out that pure copper isn't as strong or durable as alloyed copper is, making this Michigan copper best suited to decor!

Turns out that pure copper isn't as strong or durable as alloyed copper is, making this Michigan copper best suited to decor!