Nephrite Nephrite Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite or actinolite (aggregates of which also make up one form of asbestos). The chemical formula for nephrite is Ca(Mg, Fe)SiO(OH). It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene. While nephrite jade possesses mainly grays and greens (and occasionally yellows, browns or whites), jadeite jade, which is rarer, can also contain blacks, reds, pinks and violets. Nephrite jade is an ornamental stone used in carvings, beads, or cabochon cut gemstones.
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