There's a few places to mine for Herk's as the locals call them. I've never been to the Herkimer mine but I have been to the Ace of diamonds and recommend against it. The owner was rude, disinterested and just plain grumpy, even to children who asked him about their stones. I've heard good things about Crystal Groves family atmosphere but they apparently have a lack of larger vugs. I personally have my own claim in Fonda, N.Y. and have been mining them there for around 4 years now. There is a wide variety of crystal habits with the Herk's and I've dug a few unusual specimens and matrix pieces as well. Fonda has great quality calcite/Herk matrix pieces, one of which I had in a trade for 8oz of silver wire. I've also dug, skeletals, smokies, bridge crystals, one was described as a slightly sceptered double bridge crystal with a barbell tail as well as black diamonds and a phantom. There is a wide variety of inclusions as well. Pyrite, marcasite, anthraxolite (also in spheres), and more. One of my latest stones stands on a beaver tail of what looks like thin sheets of rusty metal. Still not sure what that one is. I gave one to a friend that has a small metallic attachment at the point that looks like a conch shell of sorts. Then you have the clusters and druzy crystal lined pockets too. If anyone wants to stop out I got dirt I want moved and there is crystals in the dirt level as well. Sift all you want or I can give you a tour of the mine and show you some more options. My personal goal is to dig one of the monster Herk's. I've heard of a few crystals popping out in the 15lb range so there is a little variety. Oh that and I'd love to dig a hopper crystal too. I've definitely dug a few oddballs and some I don't even know how to describe them. Jason