In Burma , where some of the most beautiful colors are mined, spinel was recognised as a separate gem species since 1600 but in other countries the masquerade continued for hundreds of years. Historically, fine red spinels were esteemed as much as ruby, and sometimes even more.
Next to ruby and the rare red diamond, spinel is the most expensive of all red gems. Spinels were most often referred to as “balast rubies” which may have referred to colour or to country of origin.
The most famous is the Black Prince’s Ruby, a magnificent 170-carat red spinel that currently adorns the Imperial State Crown in the British Crown Jewels after a long history: Henry V even wore it on his battle helmet! The Timur Ruby, a 352-carat red spinel now owned by Queen Elizabeth, has the names of the Mughal emperors who previously owned it engraved on its face, an undeniable pedigree!
With a hardness of 8 and no cleavage planes, spinel is a tough and durable gemstone suitable for any kind of jewellery.
Its’ lustre is vitreous and rough crystals can be transparent, translucent or nearly opaque. A member of the isometric system, the octahedron is the typical habit. Dodecahedrons and combinations of other isometric forms are also common. Many crystals are twinned on the plane of the octahedral face forming flattened triangular forms known as “spinel twins”.
Today, spinel is a favourite of gem dealers and gem collectors due to its brilliance, hardness and wide range of spectacular colours. Vivid traffic light red and cobalt blue are the most expensive colours for spinel and nice stones over 3cts. in size are always a rarity.
Top quality red spinels display superb bright and saturated red colours that actually fluoresce, or glow, in natural light. Pure colourless natural spinel is extremely rare and natural white spinels always show a trace of pink. Star spinels are found occasionally and they may display either four or six rays depending on their orientation. Spinel also comes in beautiful blues which are sometimes called cobalt spinel, but these are very very rare.
Because spinels made in a laboratory are often used for imitation birthstone rings, many people think “synthetic” when they hear the name “spinel.” They have often never even seen the real thing.
In fact, the main thing holding back greater recognition for spinel is rarity. Fine spinels are now more rare than the rubies they used to imitate. Strangely, they are also more affordable: in the gem world, too rare can be a drawback because so few people even get a chance to grow to love these gem varieties.
In addition to Burma, now known as Myanmar, spinel is mined in Sri Lanka, Tanzania, and Tadjikstan, part of the former Soviet Union.
Spinel is a durable gemstone that is perfect for all jewellery uses.
It is most often faceted in oval, round, or cushion shapes and is not currently found in calibrated sizes due to its rarity.
Precious spinels appear strikingly clean and free of inclusions. This impression is due among other things to the lack of liquid inclusions.
The best proof of spinel is spinel and microscopic octahedra may be scattered in long chains and sinuous bands throughout inner stretches of the host crystal. Besides these mini spinels, spinel shelters a whole range of other guest minerals including albite, anhydrite, apatite, baddeleyite, calcite, olivine, and titanite.
Historically, fine red spinels were esteemed as much as ruby, and sometimes even more. Next to ruby and the rare red diamond, spinel is the most expensive of all red gems.
Sandra Kemppainen, wikipedia.
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