Bangkok gem district (Silom, Mahesak and Surawong)

Bangkok is one of the world's great coloured-stone centres, and its trade is concentrated in a few streets of the Bang Rak district: Silom, Mahesak and Surawong roads, with the Jewelry Trade Center tower on Silom at their heart. Behind ordinary office fronts sit dealers, cutting agents, exporters, jewellery manufacturers and several gem laboratories.

What you find

Ruby, sapphire and spinel above all, along with emerald, tourmaline and nearly every other coloured stone, rough and cut. Bangkok is also where many tenders and private viewings of coloured stones are held, and where much of the cutting, recutting and setting for export is arranged.

How trading works

This is a trade district, not a market for walk-in shoppers. Dealers work from offices and see buyers by appointment, usually on weekdays. Trade buyers come with introductions, a lab and a shipping agent already chosen. The Bangkok Gems & Jewelry Fair, held twice a year, is the easiest way for newcomers to meet the trade.

Visiting and buying safely

• Beware of strangers who start a conversation in the street and recommend a "government" or "special sale" gem shop: the long-running Bangkok gem scam targets tourists, not the trade.
• Several international laboratories have offices in the district; buy important stones with a report.
• Dress for business and arrive on time: meetings follow normal office etiquette.