Liwan Plaza

This guide to Liwan Plaza in Guangzhou opens on the mall's jade counters, asking how a shopper is supposed to tell real jadeite from stone that has been bleached, resin-filled and dyed to match. It traces the building's fast 1990s construction and the three centuries this district has traded jade, along with the naming system gemologists later devised for untouched jade and its treated imitations. Look for the tiny brownish or black flecks near a carved line, one of the oldest tells on this floor.