Thai Ruby

Thai Rubies are beautiful ‘Royal Red’ gemstones from Bo Rai, the former ‘King of Thai Ruby’, in Thailand’s Trat province. First referenced in 1408, Thai Ruby once fulfilled 95 percent of the world’s demand for this extremely rare and highly coveted gemstone. Ostensibly depleted since 2009, Thai Ruby is impossibly rare, making it incredibly collectable.

Hardness 9
Refractive Index 1.762 – 1.778
Relative Density 3.97 – 4.05
Enhancement Heat


Named from the Latin ‘ruber’ (red), Ruby’s beautiful hues embody the color of love, passion and romance. Thai Rubies display a Royal Red, often with attractive secondary purple flashes, due to their higher iron content reducing fluorescence. While deeper toned than Burmese Rubies due to an absence of light being evenly scattered by silk, Thai Rubies usually display a superior clarity. Royal Red Rubies typically come from Cambodia, Kenya, Madagascar, Mozambique, and Thailand.

As transparency and inclusions also affect Ruby’s color and subsequent beauty, Ruby is clarity classified by the Gemological Institute of America as a Type II gemstone (some minor inclusions that may be eye-visible). To maintain quality and beauty, our Thai Rubies have been optimally cut with an eye-clean clarity, the highest quality clarity grade for colored gemstones as determined by the world’s leading gemological laboratories, with a good shape and overall appearance. This negates color unevenness due to zoning (location of color in the crystal versus how the gem is faceted) and excessive windowing (areas of washed out color in a table-up gem, often due to a shallow pavilion).

The birthstone for July, Ruby is a truly mesmerizing gemstone with a rich history, potent symbolism, and a popularity spanning over 2,500 years. Ruby and Sapphire are color varieties of the mineral Corundum (crystalline aluminum oxide), which derives its name from the Sanskrit word for Rubies and Sapphires, ‘kuruvinda’. Trace amounts of elements such as chromium, iron and titanium as well as color centers are responsible for producing Corundum’s rainbow of colors.


Far scarcer than Diamonds, Rubies are extremely rare, highly coveted, and one of the world’s most expensive gemstones. Ruby sources include Afghanistan, Burma, Cambodia, China, India, Kenya, Madagascar, Mozambique, Pakistan, Sri Lanka, Tanzania, Thailand, and Vietnam. A major international gemstone hub, Thailand is the middle point for approximately 90 percent of the world’s Rubies as they journey around the globe.

Thai Ruby was first referenced by the Chinese traveler, Ma Huan, in 1408. He mentions a market (Chanthaburi) in Eastern Siam (Thailand since 1939) where Rubies, “…bright and clear like the seeds of the pomegranate” are sold. Thai Ruby hails from Bo Rai in Thailand’s Trat province, which also includes the Bo Waen and Nong Bon Ruby mines. In the 1960s production at Trat was revived as mining in Burma declined, and by the 1980s, Thai Ruby was supplying approximately 95 percent of the world’s Ruby. Interestingly, this affected a marketplace shift; many consumers’ now preferred their richer Royal Reds. By 1996, Bo Rai ‘King of Thai Ruby’ was a shadow of its former self, with most mining moving across the border to Cambodia. Unfortunately, Bo Rai had declined to the point of a ghost town: abandoned mined equipment littered the area, and the once thriving morning market was reduced from hundreds of miners to only a handful. By 2009, Thai Ruby was ostensibly depleted, noting ours were mined well-over 20 years ago. Thankfully, the international gem town of Chanthaburi (45 kilometers east of Trat) continues to thrive, as gemstones from around the world are brought for processing, lapidary, and trading.

Durability & Care

One of the world’s hardest gemstones (Mohs’ Hardness: 9), Thai Ruby is an excellent choice for everyday jewelry. Thai Ruby should always be stored carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.

Map Location

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