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
The Return of Rock shows. Lewis had also recorded "Live at the Star Club, Hamburg" in 1964, an album that many consider one of the wildest performances ever. Lewis had been touring non-stop since the scandal and his ability to play ferocious rock and roll had remained undiminished in the face of dwindling sales. Hoping to recapture his past success, Lewis and producer Shelby Singleton began work on a new rock and roll album. In the liner notes, Robert Tubert wrote: "Rock is the music which vibrantly records the time in which we live ... and Jerry Lee Lewis is one of its greatest