Spinel is a gemstone that is highly regarded by gem dealers and collectors, but is still largely unknown to the general public. Since the production is too limited to supply most retail jewelers, you will rarely find Spinel in your local jewelry store. The Spinel trade is mainly the province of specialized gem dealers who trade in the finest stones.
Gem aficionadoes prize Spinel for its brilliance, hardness and wide range of spectacular colors. In addition to beautiful rich reds, Spinel can be found in a range of lovely pastel shades of pink, orange, purple and blue. Spinels displaying a star, as in the video above, are unusual and very rare.
By chemical composition Spinel is magnesium aluminum oxide, and is thus close to Ruby and Sapphire (aluminum oxide). Indeed Spinel is usually found in the same locations. But where corundum has a hardness rating of 9 on the Mohs scale, Spinel is not quite as hard with a rating of 8. Nonetheless Spinel is quite hard and durable, and is suitable for any kind of jewelry.
Spinel forms as cubic crystals like Diamond. But unlike Diamond, which has perfect cleavage, Spinel has a complete absence of cleavage. Spinel is also one of the few singly refractive gemstones, a property it shares with Diamond and Garnet.
Spinel is sought after by gem dealers and collectors because it is regarded as an undervalued gem that is in many ways the equal of Sapphire and Ruby. Spinel actually has more dispersion or fire, and first time buyers are often amazed at how much sparkle they see in a well-cut Spinel. Spinel is also rarely heated or treated in any way, whereas high quality unheated Ruby and Sapphire are now very rare indeed. This makes Spinel an especially good value.
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| Mahenge Spinel and Diamond Ring in 18k White Gold |
Historically, the most famous red Spinels came from the Balas region of Afghanistan and were known as Balas Rubies. Some of the most famous large Rubies in the world, such as the Black Prince's Ruby, part of the British Crown Jewels, are actually Spinels. More recently, Sri Lanka and Burma have been the main sources for fine Spinel. The highest quality transparent red Spinel and hot pink Spinel has come from the Mogok region in Upper Burma.
But the big news in the Spinel world was the discovery in August 2007 of several huge Spinel crystals at Ipanko, near the town of Mahenge, in Tanzania. The largest of these, a 52 kg pyramid-shaped stone, displayed the vibrant orangey pinkish red color that is considered to be top for Spinel. Though the final yield of gemmy material from this rough was only a few percent, the stone yielded several thousand carats of valuable gems. The rough was faceted in Bangkok and AJS Gems was lucky enough to acquire some of the best of this rare material.
What is so special about this material is the highly saturated hot pink-red color and a unique neon-like glow. Like high quality paraiba tourmaline, the Mahenge Spinel seems to possess a kind of energy that glows even under low light conditions.
Prices on fine Spinel have risen with increased demand, though Spinel prices continue to be attractive relative to Ruby and Sapphire. When you consider that almost all the Spinel is the market is completely untreated, it is still quite a bargain compared to prices for unheated corundum.
See our collection of Fine Spinel Gems
Notable Gems from the AJS Collection
This month we feature rare Spinels from our collection. Click on any gem photo for details.
News from AJS and the Gems World
Ask the Gem Experts
Each month we answer questions from our customers. We welcome your questions and you can submit a question from our contact page.
Why is platinum jewelry more expensive than gold jewelry, when the price of gold is now much higher than platinum? It's a mystery to me, can you explain it? NB, Canada
But even when the gold price is significantly higher than platinum, you will still find that platinum jewelry tends to be more expensive than the same design in 18k gold. There are 3 reasons for that.
The first reason is that platinum is a very dense metal, about 30% denser than 18k gold. So it takes more grams of platinum to make the same jewelry design. Second, there is an issue of purity. 18k gold is an alloy with 75% gold, while platinum jewelry is typically 95% platinum. So when we combine these 2 factors, a ring design that weighs 5.5 grams in 18k gold will weigh about 7.9 grams in 950 platinum. Because of the difference in purity, the 18k gold ring will contain about 4.12 grams of gold while the platinum ring will have about 7.5 grams of platinum, a difference of about 80%!
Finally, there is also a difference in the cost of making jewelry in the 2 metals. Gold is extremely malleable and is easy to bend and turn into different shapes without breaking. Platinum is more brittle and harder to bend and hammer into shape, and it has a higher melting point. So it usually takes more skill and effort to make platinum jewelry.
