Iron Oxide Crystals

Ohio History

Crystal Combos

As we advanced into the third underground "room" of crystals, our tour guide pointed out the unique "dual formations" in the Caverns. They are combinations of iron oxide sediment at the top and regular calcium crystals at the bottom. These multi-colored formations are thus a mixture of rusty brown and pure white. Can you see both stalactite and column dual formations in the picture above? According to the Caverns' website, these formations are quite rare but Ohio Caverns features a large number of them.

Iron Loopholes

There was plenty of other iron in the underground caves as well. The orange color in the left side and center of this picture is actually hundreds of teeny crystals formed by the iron oxide. And in the back center I believe is a solid iron column, though it's hard to tell. These orange hues were so pretty - it was hard to believe it's the same process that leaves orange hard water stains all over the shower walls!