You can freeze your gallstone(s). I once had an eight ounce container of various stones. Then, the freezer stopped working. All I had left was a container of smelly, waxen green stuff. The longer the stone stays at room temperature, the faster it will melt if its a true cholesterol stone. I never passed a single stone larger than a grape. The few that were larger were a bunch of stones massed together, I assume they were joined together in the colon. The smaller large stones had rings like a tree trunk when they were sliced in half, but they were solid stones.