Glossary
Thailand and Cambodia
The border region around Chanthaburi and Pailin was for decades one of the great sources of ruby and sapphire. The stones come from basalt regions: volcanic eruptions carried already formed crystals to the surface.
Stones from basalt
Rubies from Thailand are richer in iron and look darker than stones from Myanmar. Sapphires from these areas often show blue, green and yellow. For such sapphires many laboratories state only «basalt-related origin» instead of a country.
Trading centre
The Pailin mines in Cambodia are largely exhausted, and Thailand produces little today. Chanthaburi, however, remains an important centre for trading and cutting coloured gemstones.
Read more
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Updated 2026-10-06