Ruili's jade market is not one place but a concentration of streets and trading halls where jade and jadeite — ranging from uncut rough stones to finished jewellery — are bought and sold in quantities that dwarf any other jade market in China. The Jiegao area, a Special Economic Zone on the border with Myanmar, has the highest concentration of wholesale dealers. The city centre streets around Nan Mao and the Treasure Street have more retail options aimed at tourists, though "tourist" here means Chinese domestic buyers rather than foreigners, and the prices reflect genuine commercial stakes.
The best approach is to spend time watching rather than buying. The rituals of the trade — stones wrapped in newspaper, buyers huddling over pieces with torches, prices negotiated in rapid whispers — have an intensity that makes the markets feel more like gambling dens than shops, which is partly the point. If you do want to buy, bring someone who knows jade; the fakes and mid-quality pieces passed off as premium stones are sophisticated enough to fool the untrained eye. Small carved pieces at the lower end of the market are generally safer territory.