FIFTEEN POINT EIGHT pounds, you guys, holy smokes! This ain't your run-of-the-mill Discovery Kids science kit agate. Check out this beauty that a fisherman and gem collector found along the Yellowstone River in Billings. It's so big that one commenter said the rock is so big, it's likely that one would have to build a tumbler for it. To which another commenter said to just use a cement mixer. All jokes aside, this puppy fills up half of his sink, and speaking of puppy, the dog even had to come take a look, see below.