An adze can be any tool with a sharp, cutting edge used for smoothing or carving wood. Before metal blades were introduced in the early 1800s, all woodwork was done with stone or shell tools. Stone adze blades were cut into rough shape using stone hammers and then rubbed in grooved grindstones spread with wet sand. The often very deeply grooved grindstones are still found on beaches and in, or alongside, streams throughout Fiji. Once formed the blades were polished with shark or ray skin before abrasive leaves were used to give a final shine to the stone.