A conveyor for use in a conveying plant for recovery of diamond and other precious stones, semi-precious stones and minerals, and for conveying any material includes an endless conveyor with both its feed and return portions enclosed in a pipe, with a drive for driving the belt and a return idler, with the feed portion above the return portion and the feed portion cupped by the pipe, the pipe preferably being of plastic material and supported by a steel half pipe under the plastic pipe.