Natural Spinel in Bangkok: Red, Pink and Cobalt Spinel from JTC Silom
By Ansh Gupta, second generation at KC Gems House, Jewelry Trade Center, Silom Road, Bangkok
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Alt: Loose natural red and pink spinel gemstones on a white gem paper at the Jewelry Trade Center in Bangkok
Spinel is the stone I get asked about most by buyers who already know gems. They have usually bought a sapphire or a ruby before, they have read about the Black Prince’s Ruby in the British crown that turned out to be a spinel, and they want to know one thing: where do I get a good one without overpaying?
Bangkok is the honest answer. Most of the world’s fine spinel rough from Burma, Tanzania, Vietnam, Sri Lanka and Tajikistan passes through Thai cutting houses and Silom dealers before it reaches a jeweller in London, Dubai or New York. My family has been trading coloured stones in this city since 1990, and our office sits inside the Jewelry Trade Center on Silom Road, a short walk from the GIT, AIGS and Lotus Gemology laboratories. That is the context for everything on this page.
What follows is everything I would tell you if you sat across my desk: what spinel is, how to judge its colour, where the best material comes from, how it is (and is not) treated, what it costs per carat in 2026, and how to buy it safely in Bangkok. If you only want to see stones, skip to how to buy spinel from us or browse the full natural gemstones collection.
Spinel at a glance
Property: Mineral · Detail: Magnesium aluminium oxide (MgAl2O4)
Property: Hardness · Detail: 8 on the Mohs scale
Property: Crystal system · Detail: Cubic, so it shows no double refraction
Property: Refractive index · Detail: About 1.718
Property: Main colours · Detail: Red, pink, hot pink, orange, purple, lavender, grey, blue, cobalt blue, black
Property: Key origins · Detail: Burma (Myanmar), Tanzania, Vietnam, Sri Lanka, Tajikistan, Afghanistan
Property: Typical treatment · Detail: None for most stones; heat is rare and must be disclosed
Property: Birthstone · Detail: August (alongside peridot)
Property: Thai name · Detail: สปิเนล
What spinel actually is
Spinel is its own mineral species, not a type of ruby or sapphire, even though it grows in the same marble deposits as ruby and often sits right next to it in the gravels. For centuries nobody could tell the two apart. Red spinel was simply called “ruby” or “balas ruby”, and some of the most famous royal “rubies” in Europe and Central Asia are spinels. The Black Prince’s Ruby in the Imperial State Crown and the Timur Ruby are both spinel.
Modern gemmology separated them in the late 18th and 19th centuries. Spinel is singly refractive (cubic) while ruby is doubly refractive, and spinel has a different chemistry and refractive index. Once the trade understood that, spinel fell out of fashion for a long time, which is a big part of why it is still underpriced against ruby today.
Three things make spinel special for a buyer:
1. It is usually untreated. Most spinel on the market has had no heat, no filling and no diffusion. In a world where nearly every ruby and sapphire is heated, that matters.
2. It is hard and tough. At 8 on the Mohs scale with no cleavage, spinel is an excellent everyday ring stone, harder than emerald, tourmaline or garnet.
3. It is bright. Spinel’s single refraction and good refractive index give it a lively, glassy sparkle. A well-cut red spinel often looks brighter than a ruby of the same colour.
Famous spinels in history
Spinel has a royal history that most buyers never hear about.
• The Black Prince’s Ruby is a large red spinel set in the front of the British Imperial State Crown, above the Cullinan II diamond. It has been in the English royal collection since the 14th century.
• The Timur Ruby is a red spinel of about 352 carats, engraved with the names of several Mughal emperors and Persian rulers who owned it. It is now in the British Royal Collection.
• The Great Imperial Crown of Russia, made for Catherine the Great in 1762, is topped by a red spinel of about 398 carats.
These stones are the reason spinel’s old trade name was “balas ruby”. When gemmologists finally separated spinel from ruby, many of these crown jewels were reclassified, and the market lost interest in spinel for most of the 20th century. Collectors and gemmologists rediscovered it in the 2000s, helped by big finds in Tanzania and a new generation of buyers who value untreated stones.
From mine to Bangkok: how spinel reaches JTC
Almost every fine spinel you see in the world has passed through Thailand at some point. Here is the usual route.
1. Mining. Spinel is mined mostly by small-scale and artisanal miners from marble deposits and the river gravels below them, in Burma, Tanzania, Vietnam and Sri Lanka.
2. Rough trading. Rough is sold at local markets near the mines, then carried to Bangkok, Chanthaburi or Mae Sot by trading families who have worked these routes for generations.
3. Cutting. Thai cutters in Chanthaburi and Bangkok are some of the most experienced spinel cutters in the world. They decide how to orient each crystal for the best colour and weight.
4. Selling in Silom. Cut stones come to the offices and booths of JTC and the streets around Mahesak Road, where buyers from Hong Kong, India, Europe and the US source them.
Buying at the end of that chain, in Silom, is why Bangkok prices for spinel are usually well below retail prices in London or New York for the same quality.
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Alt: A red spinel and a ruby side by side under daylight showing the brighter, glassier look of the spinel
Spinel colours and how to judge them
Colour drives at least two thirds of a spinel’s price. When I grade a spinel I look at hue (the colour itself), tone (how light or dark) and saturation (how strong or grey). Here is how each colour family is judged in the Bangkok trade.
Red spinel
Red is the classic and the most expensive colour. The finest red spinel is a pure, vivid red with no brown and very little pink or orange, medium to medium dark in tone, and bright across the face of the stone. Burmese red spinel from the Mogok area and the Namya region is the benchmark. Some Burmese reds glow under daylight because of their natural chromium content, the same effect that makes Burmese ruby famous.
What lowers the price: a brownish or “brick” cast, too dark a tone that turns black in low light, or a lot of extinction (dark patches) because of a poor cut. Orangey red (“flame” spinel) is also valued, and some collectors prefer it.
Pink and hot pink spinel
The hot pink to neon pink spinel from the Mahenge area of Tanzania changed the market when it appeared in larger quantities around 2007. Fine Mahenge spinel is intensely saturated, almost glowing, with a slight red or purple secondary hue. Burma also produces lovely pink spinel, usually a little softer and more “candy” pink, and Vietnam’s Luc Yen area produces pinks and purples.
When you buy pink spinel, look for even colour with no grey, no watery light areas in the centre of the stone, and strong brightness. A pale, grey-pink spinel can cost one tenth of a vivid Mahenge pink of the same size.
Purple, lavender and grey spinel
These are the value end of spinel and a favourite of designers. Lavender, mauve and “steel” grey spinels from Burma and Sri Lanka have a calm, modern look that suits everyday rings and stacking bands. Prices are gentle, and clean stones in larger sizes are still easy to find.
Blue and cobalt spinel
Most blue spinel gets its colour from iron and leans greyish or violet. Cobalt spinel is different: it owes its colour to trace cobalt, and the best stones show an electric, saturated blue that no other natural stone matches. Cobalt spinel comes mainly from the Luc Yen area of Vietnam and from Sri Lanka, and stones over one carat are rare. It is one of the most expensive coloured stones per carat in the spinel family and a true collector stone.
Orange, black and other colours
Orange “flame” spinel, peach and salmon tones, and opaque black spinel all appear in the Bangkok market. Black spinel is inexpensive and often used for pave and men’s jewellery. If you see “black spinel” at a very low price, that is normal; it is a different product from the transparent colours above.
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Alt: A row of natural spinel gemstones in red, hot pink, lavender, grey, cobalt blue and orange arranged from warm to cool colours
Where the best spinel comes from
Origin does not decide everything, but it does affect price and resale, and a good laboratory report will state it when it can be determined.
Burma (Myanmar)
Burma is the historic home of fine spinel. The Mogok Stone Tract and the Namya area produce reds, pinks and purples, often from the same marble host rock as Burmese ruby. Burmese red spinel with a “Burma” origin on a lab report carries a clear premium. Most Burmese spinel is cut in Thailand and traded in Bangkok and Chanthaburi.
Tanzania (Mahenge and Morogoro)
Mahenge produces the vivid hot pink and red spinel that many younger buyers now associate with the stone. Large clean crystals were found in 2007, and good Mahenge material still appears in Bangkok, but top colour in sizes over three carats is increasingly hard to find.
Vietnam (Luc Yen)
Luc Yen in northern Vietnam produces a wide range of spinel, from pinks and purples to the famous cobalt blue. Vietnamese material is often cut in Thailand.
Sri Lanka
Sri Lanka produces pastel pinks, purples, greys and blues, plus occasional cobalt spinel. Ceylon spinel is often very clean and bright.
Tajikistan and Afghanistan
The historic “balas ruby” mines of the Pamir mountains in Tajikistan and Badakhshan in Afghanistan produced many of the great royal spinels. Material still appears occasionally, usually pink to orangey pink.
Is spinel treated?
This is the question I answer every day, and the honest answer is: most spinel is not treated, but you should still ask.
• Untreated: The large majority of spinel in Bangkok is natural and untreated. It is mined, cut and polished, nothing else.
• Heat: Some spinel is heated, usually at lower temperatures, to improve clarity or adjust colour. Heated spinel is less common than heated sapphire, and labs can often detect it from changes in the stone’s internal features and spectrum. It must be disclosed, and it lowers the price.
• Filling and dyeing: Rare in spinel, but cracked stones are occasionally oiled or filled. Any filling must be disclosed.
• Synthetic spinel: Flame-fusion synthetic spinel has existed for more than a hundred years and is cheap. It is often used to imitate aquamarine, blue zircon or other stones. Synthetic spinel is a legitimate product when sold as synthetic, but it should never be sold as natural.
Our rule is simple. Every stone on our desk is described in writing: natural or not, treated or not, and how. If a stone has a laboratory report, you see the report before you pay. If it does not, we can send it to GIT or AIGS for you before the sale is final. You can read more about how our labs work in our piece on what gemmology schools see when they grade a stone.
Clarity, cut and carat weight in spinel
Clarity
Spinel is usually expected to be eye clean, meaning you should not see inclusions without a loupe at normal viewing distance. Many spinels contain tiny octahedral crystals (a natural spinel inclusion), fingerprints or “silk”. These do not hurt the stone unless they are visible or reduce brightness. A few inclusions under the loupe are actually useful, because they help a lab confirm the stone is natural.
Cut
Because spinel is a bright stone, cut matters more than many buyers think. Common faults in Thai and Burmese native cuts are a deep belly (to save weight), windowing (a see-through area in the centre), and an off-centre culet. A precision recut can lose 10 to 20 percent of the weight but dramatically improve brightness and value. Popular shapes in Bangkok are cushion, oval and octagon, with some step cuts and rounds.
Carat weight
Fine spinel becomes rare quickly above two carats, and prices per carat rise steeply. Red and hot pink spinel over five carats with good colour and clarity is a serious collector stone. Lavender and grey spinel stay easy to find in larger sizes.
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Alt: Close-up through a jeweller’s loupe showing tiny octahedral crystal inclusions inside a natural spinel
Spinel price per carat in 2026
These are the retail ranges we see for natural, faceted spinel in Bangkok. They are per carat, for eye-clean stones from 1 to 3 carats, with a good cut. Larger sizes, laboratory origin reports and exceptional colour cost more.
Colour and quality: Grey, steel and lavender, good quality · Typical price per carat (USD): $100 to $500
Colour and quality: Commercial pink and purple · Typical price per carat (USD): $150 to $600
Colour and quality: Fine Burmese pink · Typical price per carat (USD): $600 to $2,500
Colour and quality: Vivid hot pink Mahenge · Typical price per carat (USD): $1,000 to $4,000
Colour and quality: Commercial red · Typical price per carat (USD): $300 to $1,200
Colour and quality: Fine Burmese red, vivid, eye clean · Typical price per carat (USD): $1,500 to $6,000+
Colour and quality: Cobalt blue, fine · Typical price per carat (USD): $3,000 to $15,000+
Colour and quality: Black spinel (opaque) · Typical price per carat (USD): $5 to $30
What moves a spinel up or down this table:
1. Colour saturation. A vivid stone can cost five times a medium one of the same hue.
2. Origin on the report. Burma and Mahenge carry premiums for red and pink.
3. Size. Prices per carat roughly double between the one carat and three carat ranges for top colours.
4. Treatment. Heated spinel sells at a clear discount to untreated.
5. Cut quality. A precision cut costs more per carat but gives you a brighter stone.
If you want to compare spinel with ruby and sapphire on value, our natural vs lab sapphire price calculator shows how much corundum prices swing with treatment and size. Spinel often gives you more colour and brightness per dollar than an untreated ruby of the same size.
Spinel vs ruby: which should you buy?
I get this question a lot, so here is the short version.
Hardness · Red spinel: 8 · Ruby: 9
Usually treated? · Red spinel: No · Ruby: Yes, most are heated
Brightness · Red spinel: Very bright, glassy · Ruby: Rich, can be silky
Price for a fine, untreated 2 ct · Red spinel: Much lower · Ruby: Much higher
Resale and recognition · Red spinel: Growing · Ruby: Very high
If you want a red stone that you can wear every day, that is untreated, and that gives you the most beauty for the money, choose spinel. If you want the most recognised name, the best long-term liquidity and you are comfortable with heat treatment, choose ruby. Many of our clients end up with a spinel centre stone and use the savings on a better setting.
Natural spinel vs lab-grown spinel
We sell both, but never mixed together. Lab-grown spinel has the same chemistry and hardness as natural spinel and costs a fraction of the price. It is a good choice for fashion jewellery, for very large sizes, or if you simply want the look. Natural spinel is the choice if you care about rarity, collecting or long-term value.
Every lab-grown stone we sell is labelled as lab-grown on the invoice. You can see our lab-grown range on the lab-grown spinel page. This page is natural spinel only.
How to buy spinel safely in Bangkok
Bangkok is the best city in the world to buy coloured stones, but it also has a well known gem scam aimed at tourists. Here is how to buy spinel safely.
1. Never follow a tout. If a tuk-tuk driver, a “student” or a friendly stranger takes you to a gem shop with a special government sale, leave. Real dealers do not find customers on the street.
2. Buy where the trade buys. The Jewelry Trade Center (JTC) on Silom Road and the streets around it are where professional buyers from around the world source stones. We have been part of that trade since 1990.
3. Ask for the treatment in writing. Natural, untreated, or heated. It should be on your invoice.
4. Get a laboratory report on important stones. GIT (the Gem and Jewelry Institute of Thailand), AIGS and Lotus Gemology are all minutes from JTC. For a fine red or cobalt spinel, ask for origin as well as identification.
5. Compare in daylight. Ask to see the stone near a window. Spinel can look very different under shop lights.
6. Don’t buy to resell. Anyone who tells you that you can double your money back home is lying.
For a longer guide, read why Bangkok is one of the world’s best places to buy gemstones and our step by step how to buy page.
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Alt: The Jewelry Trade Center building on Silom Road in Bangkok where KC Gems House is based
Why buy spinel from us
I will not tell you we are the only good spinel dealer in Bangkok. There are many honest people in this building. Here is what I can tell you about how we work.
• Family trade since 1990. KC Gems House was built by my father, KC Gupta, who started trading coloured stones in Bangkok in 1990. I am the second generation. You can read more on our family business page and on my own page.
• We sit inside JTC. Our office is in the Jewelry Trade Center on Silom Road. When you buy from us, you are buying at trade level, not through a tourist shop with commissions on top.
• We source across the building. If we do not have the spinel you want, we know the dealers who do. We show you stones from several sources and tell you honestly which one we would buy.
• Treatment in writing, every time. Natural, untreated, heated, or synthetic: it goes on the invoice before you pay.
• Independent reports. Any spinel can go to GIT or AIGS before you commit. Both labs are a short walk from our desk, and AIGS is in the same building.
• We set it here. We make rings, pendants and earrings in 10k, 14k and 18k gold. See our custom jewellery in Bangkok page or the spinel cocktail ring in our catalogue.
• We ship worldwide. Clients in the UK, Europe, the US and the Middle East buy from us remotely with videos, daylight photos and lab reports before they pay.
Spinel jewellery ideas
Spinel’s hardness and brightness make it a versatile jewellery stone.
• Engagement rings. A red or hot pink spinel solitaire or a spinel and diamond three-stone ring is a strong, durable alternative to ruby. See our bridal collection for settings that suit coloured centres.
• Cocktail rings. Large lavender or grey spinels make beautiful, affordable statement rings.
• Stacking bands. Small calibrated spinels in mixed pinks and reds work well in eternity and half-eternity bands.
• Earrings. Matched pairs of red or pink spinel are hard to find, so expect a premium for a good pair.
• Men’s rings. Black spinel and dark grey spinel suit signet and gypsy-style men’s rings.
If you have a design in mind, use our custom order form or read our honest breakdown of what factory-price custom jewellery at JTC actually costs.
Caring for spinel
Spinel is easy to live with.
• Cleaning: Warm water, mild soap and a soft brush. Ultrasonic cleaning is usually safe for untreated, uncracked spinel, but avoid it for stones with fractures or fillings.
• Heat: Avoid sudden temperature changes during jewellery repair. Tell your jeweller the stone is spinel.
• Storage: Store spinel away from diamonds and sapphires, which are harder and can scratch it.
Spinel for wholesale buyers
If you are a jeweller or designer, we supply calibrated spinel in standard sizes, matched pairs and layouts, and single fine stones. Tell us the colour, size range, quantity and budget and we will put together a parcel with videos. Read more on our wholesale page.
สปิเนลแท้ ที่ JTC สีลม
สปิเนล (Spinel) เป็นพลอยธรรมชาติที่แข็งแรง สวยสด และส่วนใหญ่ไม่ผ่านการเผาหรือปรับปรุงคุณภาพ ในอดีตสปิเนลสีแดงถูกเข้าใจผิดว่าเป็นทับทิม และเคยอยู่ในมงกุฎของราชวงศ์ยุโรปมาแล้ว
เราคือ KC Gems House ค้าพลอยในกรุงเทพฯ มาตั้งแต่ปี 1990 สำนักงานอยู่ในอาคาร Jewelry Trade Center ถนนสีลม เรามีสปิเนลสีแดงพม่า สปิเนลสีชมพูเข้มจากมาเฮนเก (แทนซาเนีย) สปิเนลสีม่วงลาเวนเดอร์ สีเทา และสปิเนลสีน้ำเงินโคบอลต์ซึ่งหายากมาก
สิ่งที่ลูกค้าได้รับจากเรา
• แจ้งการปรับปรุงคุณภาพเป็นลายลักษณ์อักษรก่อนชำระเงิน
• ส่งตรวจใบรับรองจาก GIT หรือ AIGS ได้ทุกเม็ด
• ดูพลอยจริงในแสงธรรมชาติที่สำนักงาน JTC สีลม
• รับทำแหวน จี้ ต่างหู ด้วยทอง 10K 14K และ 18K
ราคาสปิเนลขึ้นอยู่กับสี ความสด แหล่งที่มา และขนาด สปิเนลสีแดงพม่าคุณภาพดีและสีชมพูมาเฮนเกมีราคาสูงกว่าสีม่วงหรือสีเทาหลายเท่า ติดต่อเราเพื่อขอดูพลอยและราคาจริง
Frequently asked questions about spinel
Is spinel a real gemstone or a fake ruby?
Spinel is a real, natural gemstone and its own mineral species. It was historically confused with ruby because both are red and form in the same deposits, but spinel is not an imitation. Synthetic spinel exists, which is why you should buy natural spinel with the treatment and origin in writing.
Where is the best place to buy spinel in Bangkok?
The Jewelry Trade Center (JTC) on Silom Road and the surrounding dealers are where professional buyers source spinel. Buy from an established dealer, never from a shop a stranger takes you to, and ask for a GIT or AIGS report on important stones. Our office is inside JTC.
How much does spinel cost per carat?
For eye-clean stones from 1 to 3 carats, lavender and grey spinel starts around $100 to $500 per carat, commercial pink and red runs $150 to $1,200, fine Burmese red and vivid Mahenge pink run $1,000 to $6,000 or more, and fine cobalt blue spinel can exceed $15,000 per carat.
Is spinel cheaper than ruby?
Yes. A fine, untreated red spinel usually costs much less than an untreated ruby of similar size and colour, and most rubies on the market are heated while most spinel is not.
Is spinel good for an engagement ring?
Yes. Spinel is 8 on the Mohs scale with no cleavage, so it is durable enough for daily wear. Red and pink spinel are popular engagement ring alternatives to ruby and pink sapphire.
Is spinel heated or treated?
Most spinel is untreated. Some stones are heated, and occasionally fractures are filled. Any treatment should be disclosed in writing and lowers the price. A laboratory report can confirm whether a spinel is heated.
What is Mahenge spinel?
Mahenge spinel comes from the Mahenge area of Tanzania and is known for its intense hot pink to red colour. Fine Mahenge spinel is among the most saturated pink gemstones in the world.
What is cobalt spinel and why is it so expensive?
Cobalt spinel is blue spinel coloured by trace cobalt instead of iron, which gives it an electric, saturated blue. It comes mainly from Vietnam and Sri Lanka, is very rare above one carat, and is one of the most expensive spinel colours.
Can I get a lab report for spinel in Bangkok?
Yes. GIT, AIGS and Lotus Gemology are all close to JTC on Silom Road. A standard identification report confirms the stone is natural spinel and whether it is heated. Origin reports cost more and are worth it for fine red, pink and cobalt stones.
Do you ship spinel internationally?
Yes. We send daylight videos and photos and, when needed, a lab report before payment, then ship insured to the UK, Europe, the US, the Middle East and elsewhere.
Talk to us about spinel
Tell us the colour, size and budget you have in mind and we will send you real videos of stones in daylight, with treatment and origin information, before you commit. You can visit us at JTC, or buy remotely.
Ask about a spinel
Explore other natural stones: garnet, zircon, star sapphire, pink and padparadscha sapphire, tourmaline, amethyst and citrine and cat’s eye chrysoberyl. Or go back to all natural gemstones.