Which location has been supplying the most commercial-quality rubies since 1991?

Mong Hsu, located in Myanmar (formerly known as Burma), has been a significant source of commercial-quality rubies since 1991. The region is known for producing rubies that boast vibrant colors and clarity, qualities that appeal to the gemstone market. The discovery of vast ruby deposits in Mong Hsu has positioned it as a leading supplier and has contributed to the global ruby trade. The rubies from this area are often recognized for their deep red color and are marketed as high-quality gemstones.

The other locations listed have historically been sources of rubies, but they do not match the impact or the volume of commercial-quality rubies supplied from Mong Hsu since the early 1990s. Thailand, for instance, is renowned for its jewelry production and trade but primarily processes rubies rather than supplying them in the same volume as Mong Hsu. Similarly, Cambodia and Vietnam have smaller-scale ruby mining operations that do not have the same level of commercial output as Mong Hsu.