Jade towers above all other hardstone carving ma- century or two) diamond cutting tools were intro- terials-rose quartz, aventurine, agate, rock crystal, duced into China, or where the high-quality jade bloodstone, lapis lazuli, turquoise, and the rest-in found in ancient pre-Columbian sites was mined- both long-term popularity and sustained value. In may never be answered. An increasing effort has spite of its intensive exploitation under widely been made, however, to pull together evidence from diverse cultures, however, little authoritative work various branches of science and bring it to...