As you’ve seen, most colored stone mines are small-scale operations in remote areas, often operated using primitive technology and tools. Communications and infrastructure might be poor. In addition, many mining areas have difficult climates and a prevalence of malaria and other diseases. These deposits are generally worked feverishly for short periods of time and then abandoned when they become less profitable or more challenging to mine.
These mining practices lead to temporary abundance of a particular gem, followed by a shortage. This fluctuation in supply usually produces wild price swings that make a gem difficult to market.
Politics and changes of government in producer countries can have a drastic effect on gem production. For centuries, the Mogok region of Myanmar (formerly Burma) was the world’s most important source of fine rubies—known as “Burmese” rubies—that commanded high prices in upscale jewelry salons and auctions. In the 1960s, a military coup in Myanmar caused this supply to shut down.
Neighboring Thailand also had ruby mines, but the market generally preferred the bright Burmese rubies to darker Thai rubies. Rapid advances in heat treatment made Thai ruby attractive, and suddenly Thailand’s ample supplies of smaller, less expensive rubies were just what the market needed. Thai ruby supported the industry’s needs for more than two decades, but by the late 1980s, even those supplies began to run out.
In the meantime, miners found a rich new ruby deposit in Myanmar. This deposit became the most important source of ruby during the 1990s. In the space of 30 years, the world’s premier ruby supplier had switched from Myanmar to Thailand and back to Myanmar again.
The Burmese rubies of the 1960s were notably more intense than the darker, redder ones from Thailand that became so commercially important in the 1970s and 1980s. When Thai ruby ran out in the early 1990s, dealers had to change back to Burmese rubies—this time from a different source in Myanmar—with subtle differences of their own.
By 2015 a relatively new discovery in Mozambique became the world’s leading ruby supplier. A large publicly traded company brought their mining expertise and set up an auction system similar to one they had used for selling Zambian emerald rough. Their large-scale, sophisticated mining operation and controlled supply system exist alongside independent miners working small pits by hand with simple tools.
Each time the source changed, colored stone wholesalers and dealers had to educate their customers to accept changes in ruby price, general appearance, and quality. Because the jewelry industry clings to tradition and doesn’t accept change very readily, it takes time for wholesalers to get jewelry manufacturers and retailers to accept stones of noticeably different appearance than the ones they’re used to. This is just one example of how changes in supply can affect the colored stone market. Consumer demand is another factor.
