57 Limestone, a 3/4 inch chipped stone about the size of quarter is most common. Some folks prefer the 46D or 411 Limestone, a 3/4 inch down to dust packing stone, or 304 Limestone, a 1.5 inch down to dust packing stone which is a little more coarse and more commonly used on farm lanes or as base material for small areas or under asphalt.