Mae Sai is the northernmost town in Thailand, in Chiang Rai Province, situated immediately across the Sai river from Tachileik in Shan State, Myanmar. Although it is dwarfed by Bangkok and Chanthaburi as a Thai gem-trade centre, Mae Sai holds a long-standing role as a border conduit through which Burmese gem rough has historically entered the Thai trade and onward to international markets.

Trade role

From the late 20th century onward, Mae Sai operated as one of the principal land crossings for Burmese ruby, sapphire, jade and spinel rough headed for Chiang Mai, Bangkok and Chanthaburi cutting houses. The trade has fluctuated with the political situation in Myanmar, the changing Thai-Myanmar border regime and, more recently, with sanctions affecting Burmese ruby and jade. Periods of armed conflict in Shan State, particularly affecting the Mong Hsu ruby producing area, have intermittently shifted material along the Mae Sai-Tachileik route or away from it depending on local conditions.

Material handled

Mong Hsu ruby (discovered 1992) was a major component of the rough crossing through Mae Sai during the 1990s and early 2000s, much of it heat-treated and lead-glass-filled in Bangkok before reaching the international market. Burmese spinel from the Namya and Pyant Pyaung deposits, jade from the Hpakant area (more often routed via Mandalay-Ruili to China but with overflow to Thailand), and various coloured-stone rough have all moved through the border at different times.

Sanctions context

US sanctions imposed under the Tom Lantos Block Burmese JADE Act of 2008 and subsequent measures affected the legal status of ruby and jadeite of Burmese origin in the US market. Material moving through Mae Sai has been subject to varying levels of disclosure and chain-of-custody scrutiny. The reopening of formal Burmese ruby trade after 2016 and the renewed sanctions following the 2021 coup have continued to reshape the practical role of the border crossing for the gem trade.