Spinel Engagement Rings
By Jared James · Last updated 17 May 2026
Quick answer
Spinel is one of the most undervalued fine gemstones. It rates 8 on the Mohs scale, is almost always untreated and comes in red, hot pink, cobalt blue, lavender, grey and black. For centuries it was mistaken for ruby, which is why some of the most famous "rubies" in royal collections are actually spinel.
What spinel is
Spinel is a magnesium aluminium oxide that forms in the same conditions as ruby and sapphire. It is singly refractive like diamond, which gives it a clean colour and lively brilliance. Untreated natural colours are the norm, so what you see is what the earth produced.
Colour and look
Red spinel can rival ruby in colour and is sometimes more saturated. Cobalt blue spinel from Vietnam and Tanzania shows a vivid electric blue that no other gem matches. Hot pink spinel is popular for engagement rings. Lavender, grey and black spinel are increasingly used for modern, minimalist designs.
Hardness and durability
Spinel is 8 on the Mohs scale with very good toughness. It is one of the hardest coloured stones below sapphire, with no cleavage issues. Excellent for engagement rings and everyday wear.
What to look for
Colour saturation is the main value driver. Red and cobalt blue spinel command the highest prices. Eye-clean clarity is normal. Cut quality affects how lively the stone reads. The almost universal lack of treatment is a strong point in spinel's favour.
Treatments and origins
Spinel is almost always untreated, unlike ruby and sapphire. Myanmar is the historical source for fine red and pink spinel. Vietnam and Tanzania produce cobalt blue spinel. Sri Lanka, Tajikistan and Madagascar are also sources. Lab-grown spinel exists but is less common in fine jewellery than lab-grown corundum.
Best uses
Red and hot pink spinel make excellent engagement ring centres at lower prices than ruby with similar look. Cobalt blue spinel is a striking statement stone. Grey and black spinel are popular in modern designs. Spinel pairs well with both warm and cool metals.
Care
Clean with warm soapy water, ultrasonic or steam. No special precautions are needed. Store separately from diamond and sapphire, which could scratch it.
Price
Spinel is undervalued compared to ruby and sapphire of similar colour and quality. Fine Burmese red spinel reaches premium prices but still costs less than ruby at the top end. Hot pink spinel from East Africa is widely available at sensible prices. Cobalt blue spinel is rare and priced accordingly.
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Frequently asked questions
- Is spinel a real gemstone?
- Yes, and a very respected one. Spinel was mistaken for ruby for centuries because they form together and look similar. The Black Prince Ruby in the British Imperial State Crown is a 170 carat red spinel.
- Is spinel treated?
- Almost never. Most spinel on the market is completely untreated, which is unusual for coloured gems and one of the strongest arguments for spinel as a buyer.
- Is spinel hard enough for an engagement ring?
- Yes. At 8 Mohs hardness with no cleavage and good toughness, spinel is one of the better coloured-stone choices for everyday wear.
- Why is cobalt blue spinel so expensive?
- Cobalt blue spinel is rare. The colour is unique and the supply, especially from Vietnam and Tanzania, is limited. Fine stones reach prices similar to good sapphire.
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