Nephrite "hei-tiki" (neck pendant). These are believed to have their own "mana", are handed down as valuable heirlooms, and often given as gifts to seal important agreements. It has also been used for a range of tools such as adzes, as Māori had no metal tools before European contact. Commonly called "greenstone", jade jewellery in Māori designs is widely popular with tourists. Stone is often imported from Canada, China and Siberia, and Ngai Tahu runs a pounamu certification scheme to verify the authenticity of New Zealand stone. Nephrite Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite
Ornamental turning established his workshop in London and built a reputation as a maker of high-class lathes and tools. Many of his customers were among the monarchs and nobility of Europe and England became the world centre for the pastime of ornamental turning. The Holtzapffel firm continued to make lathes until 1927 by which time they had produced a total of 2557, serially numbered, many of which were equipped for ornamental turning. Other engineers copied or varied his designs but none were so prolific in their manufacture. The hobby of ornamental turning declined rapidly following the invention of the motor-car which, by