Well this has been sitting in the dark for quite sometime but not how you may have intended! It was the darkness found on the inside of a very lonely ammo can. We actually own a geocache that is in a cave, Black Angus - A Cool Cow Caving Cache http://coord.info/GC4C4JK but will not likely be back to that area for awhile. I'll see if I can find another good spot to drop this creepily cool coin.