Thai rubies

Next in order of quality, Thai rubies come second. Thai rubies come with rather darker undertones caused by the presence of iron along with chromium. Thus you find the Thai rubies with brownish to burgundy hues. Also known as Siam rubies, these of course are no match for their Burmese cousins. Most of them are heat-treated. Chantaburi and Trat provinces lying in the south-east of Bangkok are famous for ruby mining.