The informal way gems are bought and sold makes it hard to get accurate trade figures. Here, a buyer inspects goods for sale in Teofilo Otoni, Brazil. Photo by Elana Verbin. Unlike most source countries, Colombia exports a large percentage of its gems directly to consuming nations. Miner photo by Mark Lurie.
Some mysteries are perpetual.
Just as we will never know what Mona Lisa was smiling about, or how Baywatch became an international hit, we may never know exactly how big the market for colored gemstones is. Anyone who sits down to try to come up with a realistic figure immediately runs into problems. First of all, unlike diamonds, colored gems aren't a single commodity - there are dozens of different types of gems, with different sources and different values. Mining tends to be done on a small scale in remote areas, and the people who buy the gems don't even want their customers to know how much they paid, let alone customs officials. There are clues to this mystery, however, in the form of international trade data and anecdotal evidence from people in the trade.