Caledonite is a rare mineral that contains lead, copper, sulfur, and chlorine. It is usually found in the oxidized zone of lead and copper deposits. Though not an everyday term, there are a few similar words that you might come across in the mineral world. For instance, atacamite is a green, copper-rich mineral that often appears alongside Caledonite. Azurite is another blue-hued mineral that frequently appears in the company of copper veins. Similarly, oroite is a pale blue mineral that, like Caledonite, contains lead and copper. These minerals may not be interchangeable, but they all speak to the richness and variety of our planet's natural resources.