Spinel Gemstone: History & Brilliance
The Black Prince’s Ruby in front of the Imperial State Crown of the United Kingdom
For years spinel was overlooked, often because it was mistaken for something else. It has since earned its place on its own merits: exceptional brilliance, a hardness of 8 on the Mohs scale, and a natural colour that almost never needs treatment. Sapphire and ruby are routinely heat treated to improve colour and clarity, and that treatment affects their value. A fine spinel is usually exactly as it came out of the ground.
Complete Guide to Spinel Jewellery
Vivid Colour Spectrum
Are Spinel Gemstone the Same as Sapphire and Ruby?
Spinel is often found in the same deposits as ruby and sapphire, forming alongside corundum in the marble and gem gravels of Burma, Tanzania and Sri Lanka. That is a large part of why its vivid reds were read as ruby, and its royal blues as sapphire, for centuries. Several stones long catalogued as historic rubies have since been shown to be spinel, and many now sit in important jewellery collections under the wrong name. The colour range is wide: hot pink through to a quiet, smoky grey, and on into the soft lilac of this Asscher lilac spinel ring, a bezel-set commission with gypsy-set diamond shoulders.
Why Spinel Gemstone Sparkle like Diamond?
Spinel is singly refractive, the same as diamond, while ruby and sapphire are doubly refractive. In practice, light passes through a spinel along a single path, so its facets return a clean sparkle with no visible doubling. Spinel crystallises in the cubic system, which makes the crystal highly symmetrical and gives it good hardness and an even optical character.
Rare Varieties: Mahenge & Cobalt Blue
Mahenge Spinel (Vivid Pink/Red)
Spinel is known for its vivid red, a colour once so convincingly ruby-like that famous rubies in royal collections, the Black Prince’s Ruby among them, later proved to be spinel. In recent years the stone has also become known for hot pink and orange-red varieties. The deepest reds are mined in Burma, and the neon pink-red comes from a town in Tanzania called Mahenge.
In 2007 the Mahenge field produced a single spinel crystal of around 52 kilograms, and the attention that followed put the deposit on the map for its vivid hot pink and orange-red stones. Because spinel is singly refractive, like diamond, those colours hold their sparkle from almost any angle.
Mahenge spinel is now well known to collectors and to the wider public. Its neon quality, much like the Brazil paraiba tourmaline, is hard to mistake for anything else.
Cobalt Blue Spinel
Is Cobalt Blue Spinel Worth Investing?
Cobalt spinel is a variety of the same mineral family, found in Tanzania alongside the Mahenge pink material, as well as in Sri Lanka and Vietnam. It takes its name and its vivid blue from traces of cobalt in the crystal.
The most sought-after colour is a rich, saturated blue with no hint of green or grey. Stones range from light to dark, and the finest show an electric blue close to a cornflower sapphire.
The best known source for this electric blue is Luc Yen in northern Vietnam, and as with most spinel, colour is what sets the price.
Overhype in Cobalt Blue Spinel
Cobalt blue spinel has been through a sharp price cycle. Certified cobalt-blue stones from Tanzania and Sri Lanka were asking several thousand US dollars per carat at the peak, and prices have since come back down noticeably. If a vivid blue is what you want, it is worth comparing against an unheated cornflower or royal blue sapphire before you commit.
Grey and Violet Spinel Commissions
Not all spinel is loud. The grey, violet and lavender end of the range has quietly become one of our most requested for engagement rings, chosen by people who want colour without a bright stone.
One commission was an emerald-cut bluish grey spinel that a client sourced himself, matched as closely as he could to his partner’s eyes, then set simply so the colour did the work. Another paired a bluish grey spinel with two trillion-cut diamonds and art deco detailing on the shoulders, in rose gold to warm the cool stone. A third, a purplish grey spinel, was designed with the couple at the bench.
Grey and violet spinel is almost always untreated, and it sits well below sapphire on price for a similar look. That is a large part of the appeal. See our lavender violet spinel ring for a pastel version.
Investment in High-Quality Spinel
Spinel is a durable stone: a hardness of 8 on the Mohs scale and only indistinct cleavage, which means it resists chipping better than a stone with perfect cleavage such as diamond or topaz. That toughness is part of why it wears well as an everyday ring.
Spinel is also bought as a collectable in its own right. Fine stones have climbed in price over the last decade as more buyers, not only specialist collectors, have come to know the material.
Customised Jewellery & Engagement Ring
Between its hardness, its lack of treatment and its brilliance, spinel suits jewellery that gets worn daily. It pairs well with diamond accents in white or yellow gold, where the contrast lifts the colour. If you are drawn to customised jewellery, or simply looking for a stone that is a little different, it is worth handling a few in person.
Experience the unmatched brilliance and vibrant hues of spinel gemstones at GIOIA Fine Jewellery, Singapore’s top custom jeweller specialising in rare coloured gemstones. From mysterious greyish blues to vivid neon pinks, our custom designs are perfect for every occasion. If an engagement ring brought you here, explore how we build a custom engagement ring from first sketch to final polish. For a wider range of rare stones set into engagement rings, browse our coloured gemstone engagement ring collection. We also set spinel into customised bangles, including our honeycomb and botanical garden designs. Drop by today and discover the perfect spinel gem to add to your collection!
More spinel from our workshop: a pink spinel ring, a red spinel ring, a Mahenge pink spinel piece, a lavender violet spinel ring, and a cluster spinel ring.
A Colour-Change Spinel & Sapphire Ring
This piece pairs a colour-change spinel with sapphire in one setting.