A surprisingly interesting (and fairly in-depth) picture book that introduces children to minerals - which include metals and gems. Many full color photos highlight and enhance the text, which covers topics such as Mohs' Scale of Mineral Hardness, ice crystals, cleavage planes (the way minerals break when cut) of various minerals, metals in their natural state, special metals like gold, silver and platinum, how various minerals form and what they look like in their natural state. My children and I found this to be quite an interesting book.