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Sourcing Gemstones from Thailand

Sourcing Gemstones from Thailand

Thailand is second only to Brazil as the largest producer of gemstones in the world. Its capital, Bangkok, is also hailed as the world’s gemstone capital—being the global centre for cutting, polishing, and trading gemstones of all kinds, from industrial to commercial grade.

This blog gives an overview of Thailand’s gemstone industry and what gemologists, jewelers, and private collectors alike can expect from sourcing gems there. However, since Thailand also has a thriving synthetic gemstone industry, we’ve outlined steps to safeguard your purchase and ensure that you’re paying a fair price for it.

Find legitimate gemstone suppliers in Thailand

Gemstones Common in Thailand

A variety of aluminium oxide or the mineral corundum, rubies have a pink to blood-red or pigeon-blood color, which is attributed to the element chromium. One determinant of a ruby’s quality is its color—the redder the stone, the higher its value. Around 70% of the world’s high-quality rubies are from Thailand, mostly from the mines located at Chanthaburi-Trat district in the southeastern part of the country. 

Also a variety of corundum, a sapphire contains trace amounts of iron, titanium, chromium, vanadium, or magnesium—the higher the iron, the darker the blue. However, there are other variants, including gray, black, purple, green, and a pinkish-orange called padparadscha. Sapphire and rubies are often found in the same locations, including Kanchanaburi, Chanthaburi, Si Saket, Ubon Ratchathani, Phrae, Phetchabun, and Sukhothai in Thailand. 

Most people know jade as a rich green gemstone, but it can also be found in lavender, orange, blue, black, yellow, red, and white. While jade from China is the most popular, the most expensive is jadeite from Myanmar, which has an almost transparent quality and vibrant emerald color. Myanmar jade can be sourced across the border in Thailand, at Mae Sot, a gateway between the two countries.

Tourmaline refers to a gemstone family that comes in almost every color, with some having more than one color in the same stone. Jewelers and gemologists use trade names for different colors of tourmaline such as rubellite (red), indicolite (blue), chrome tourmaline (green), schorl (black), and canary tourmaline (yellow). Some of Thailand’s top  tourmaline sellers can be found in Bo Rai, Pong Nam Ron, Khao Saming, and Nam Yuen.

“The Black Prince’s Ruby,” which is part of the UK’s Crown Jewels, and “Catherine the Great’s Ruby,” made for Empress Catherine II of Russia, are in fact, not rubies but both spinels. Sharing the same rich red coloring as rubies, a spinel has a characteristic octahedron crystal shape like that of back-to-back pyramids. However, this gemstone also comes in blue, purple, yellow, orange, and pink variants.

A gemstone popularly known for its yellow, orange, and brown color, the topaz actually comes in other colors and colorless variants, as well. The most valuable of types are the pink and red stones, followed by orange and yellow. The blue topaz used to be rare but its value has declined with the surge in supply. Chanthaburi in Thailand is a good source of topaz, especially the weekend markets on Gems Road. 

Learn more from the GIA Gemstone Encyclopedia

Reminders When Buying Gemstones in Thailand

Thailand is a leading global supplier of colored gemstones and finished jewellery, which are among the country’s top-performing export products. The most popular gemstone hubs in the country are Chanthaburi, Bo Rai, Pong Nam Ron, Khao Saming, and Nam Yuen. 

The Thai Government has mandated favorable tax exemptions, in a bid to increase the industry’s global competitiveness. To further safeguard buyers, stringent trading policies and regulations are also managed and implemented by duly recognized industry organizations. 

The country is not just a top source of gemstones globally, it also boasts of the largest jewelry manufacturing base and among the highest concentration of talented jewelers and cultivated artisans in the world. 

Moreover, as a prerequisite for sourcing gemstones, potential buyers should first check the Thai Gems and Jewelry Traders Association website for the list of reputable gemstone dealers and traders. Legitimate sellers would most likely be members of the association.

Organizations including the International Gemological Institute, and Gems and Jewelry Institute of Thailand evaluate the value of gemstones sourced from the country through a battery of assessments, process compliance, and quality standard requirements. 

When purchasing exclusive gemstones, serious buyers typically require a gemstone certification, which essentially guarantees the authenticity and value of what you’ve paid for. A gemstone certificate is also useful if you want to sell your gemstone in the future.

Browse Colored Gemstone Testers from Presidium

Why Presidium for Gemstone Testers

If you are a serious buyer or seller of gemstones, you would want to be sure of the true value of the gems that pass through your hands. As an added layer of protection for your investment, you need the most updated instruments and technology, from a trusted brand.

Industry pioneers would have the most experience and expertise, and one such forerunner is Presidium Instruments Pte Ltd (est. 1979). Presidium is the world’s first company to launch groundbreaking gemological instruments catering specially to the jewelry industry. 

Available in more than 40 countries, Presidium products include gemstone testers that determine refractive index, UV transmittance, thermal conductivity, and/or reflectivity. Presidium’s gemstone testers and complementary products are as follows: 

The Presidium Gem Tester II (PGT II) is the industry’s one and only handheld gem indicator and digital tester for application in 16 common colored gemstones. The probe consists of two linked thermometers: one which is heated electronically while the other is cooled by the gemstone being tested. The difference in temperature creates an electrical output, which is then amplified and displayed.

The Presidium Gem Indicator (PGI) is a pioneering handheld tester specifically for colored gemstones. It identifies up to 31 different types of colored gems based on their thermal conductivity and comes with the Presidium patented refined changeable probe tip, which ensures minimal equipment downtime. The PGI features a color input function that allows users to select from a range of 12 common colors. 

The Presidium Duo Tester II (PDT II) is the only comprehensive tool on the market that combines two proven testing methods for gemstones, based on both thermal conductivity and reflective indexes. Coated gemstones can also be generally tested with the PDT II. With the industry’s thinnest probe tip size of 0.6mm, PDT II tests gemstones as small as 0.02ct.

The Presidium Refractive Index Meter II (PRIM II) is a desktop digital tester that is used for the accurate measurement of broad-range R.I. values, from 1.000 to ~3.000. The PRIM II can instantly identify colored gemstones without the inconvenience of using messy RI liquids. It comes with a complementary proprietary software to help users verify the type of stone based on various gemstone properties.

The Presidium Synthetic Ruby Identifier (SRI) is a ground-breaking desktop device that instantaneously identifies synthetic (flame fusion) rubies through its characteristic high UV transmittance. It utilizes UV light with auto cut-off and gives quick results with clear indicator lights to measure the UV transmittance ability of ruby gemstones. 

The Presidium Gem Computer Gauge (PGCG) is an advanced digital computer gauge that measures gemstone dimensions, estimates gemstone weight, and identifies up to 9 different cuts. The PGCG comes with a software that lists the S.G. value, R.I. value, and hardness measurements of 133 common gemstones in the market for handy reference.

The new and improved Presidium Carat Scale – 100n (PCS-100n) measures gemstones up to 100.00 carats without the need to be calibrated each time the scale is shut off. The PCS-100n comes with a corresponding weight reference of 100.00ct/20g for calibration. This compact and portable scale can also be powered by a USB adaptor.

Learn more about Presidium from our clients