The two round grindstones recovered from the shipwreck would have been mounted on a spindle and crank apparatus to sharpen larger tools and bladed weapons. The whole stone has a 16-inch diameter and 3 inch thickness. The diameter of the partial grindstone is estimated at 15 by 4 inches. There is a possibility it had been broken long before and was simply part of the ship's ballast. Both grindstones show heavy use wear.