Buygemstone.net

Jade, being such a durable material, has always been difficult to shape. In all the history of jade carving there have been few developments to facilitate the process. As with any kind of carving, the operation consists of shaping the jade by rubbing it with an abrasive. Technology has brought about the improvement in abrasives, the introduction of various improved rubbing tools, and the conversion from human to machine-powered rubbing.
Eyewitness accounts of jade working by the early Maoris of New Zealand give us some insight into methods that must have been commonly used in all early jade-carving cultures. With his kuru (large jade hammer) the miner broke out pieces of pounamu (jade). To assist in the breaking, grooves were cut by rubbing with kiripaka (mica schist). These grooves helped to limit breaking to predetermined directions. Today jade is used frequently fo wedding bands. The final cutting and polishing were performed by long periods of rubbing with a hard stone, the hoanga. Apparently, even the early Maoris had stumbled on the pirori (rotary drill) for cutting and shaping the jade pieces. Unlike those of other primitive carvers, these drills were neither stone-tipped nor hollow; either of these special kinds of drills would have expedited the work well beyond anything possible with the simple rotating stick, sand, and water method they used.