Where the trade buys and sells in person: gem markets, trading districts, diamond exchanges and gem towns, with what is traded and when to go.
Trading district
New York, United States
Traded: Diamonds, coloured stones, jewellery manufacturing and retail
The block of West 47th Street between Fifth and Sixth Avenues: jewellery shops at street level, and dealers, cutters, setters and laboratories in the exchange buildings above. The Diamond Dealers Club is the trade's exchange.
Gem market
Bogotá, Colombia
Traded: Colombian emeralds, rough and cut
Emerald dealers (esmeralderos) trade on the street around Avenida Jiménez and Carrera Séptima by the Plaza del Rosario, and in the emerald trade buildings nearby. Imitations and synthetics are offered to unwary buyers: buy through established dealers and with a laboratory report.
Gem town
Teófilo Otoni, Brazil
Traded: Aquamarine, tourmaline, topaz, alexandrite and quartz; rough and cut; mineral specimens
Brazil's gem trading town in the gem-rich northeast of Minas Gerais, with more than 2,000 traders and a large cutting industry. It hosts the FIPP international gem fair, held since 1989.
Places, not businesses: JewelLoop does not rank, recommend or endorse any dealer. Days and hours change, so check locally before you travel. Street markets also sell imitations, synthetics and undisclosed treatments: buy important stones with a report from a recognised laboratory, and follow the export and customs rules of every country involved.