There are differing explanations of what makes a stone a gem. But in those various definitions, certain characteristics invariably come to the fore. To be considered a gemstone, a true jewel, the item must be rare, durable and desirable. People have to want the thing. The first trait, its rarity, is always essential, and for gem collectors, the rarer the better.
There is of course the subset of ultra-rarities within this exclusive provenance. In the first part of the 20th century, Austrian gemologist, Edward Charles Richard Taaffe (1898-1967) an exceptionally titled gentleman, identified one of these rarest of the rare stones. But here’s the kicker. It was already faceted and polished when he stumbled upon this as of yet unidentified species. How odd. The year was 1945. Keep in mind, the determination of a gemstone involves a systematic plan of discovery. Many clues that are recognizable in a rough crystal help facilitate its determination. Having already been cut and polished potentially eradicated some of the stone’s tell-tale identity. For example, a spinel crystal would display its cubic crystal habit which aids in its determination. Taaffeite, by comparison forms in hexagonal crystal systems.
A New Horizon & New Stone
Following WWI, Taaffe emigrated to Ireland to work as a gemologist. There he obtained a large collection of faceted stones extracted from old jewelry owned by a Dublin jeweler. After close examination, he saw that a purple Sri Lankan spinel-like stone displayed a birefringence that is absent in a singly-refractive spinel stone. Perplexed by this phenomenon, Taaffe sent the stone to the London Chamber of Commerce’s laboratory for further study. After exhaustive analysis, the purple stone was finally recognized as a ‘new’ unidentified mineral. In 1949, it was further established when a second specimen turned up.
Not only was Taaffeite, as the stone became known, a gemological oddity, but its discovery in a cut and faceted state made it a double peculiarity. We now know the composition of Taaffeite is beryllium, aluminum and magnesium. Spinel is made of aluminum magnesium oxide. So there you go.
The Taaffeite Difference
What helps this stone keep a polish is its hardness (Mohs 8-8.5). Other exotic gemstones are likewise beautiful but are so soft that they are best reserved as mineral specimens. For example, fluorite is produced in some staggering color combos, but with its hardness of just 4 on the Mohs scale, its use in jewelry is dodgy at best.
Speaking of fluorite, we know that Taaffeite occurs in carbonate rocks alongside fluorite and mica. Because of its similarity to spinel, (except for its defining separation due to double refraction) it was mistaken for spinel for years. The material is actually found close to deposits of spinel and tourmaline. Today, this extremely rare stone is turning up in alluvial deposits in Sri Lanka and southern Tanzania. Lower grade taaffeite appears in China’s limestone sediments.
The first discovery of Taaffeite was with that faceted purplish mystery stone. Since then, Taaffeite has popped up in some other alluring hues like shades of pink and purple, including mauve, lilac and violet. But it also can occur in reds, browns, blues, not to mention colorless or greys and greens. Still, the world wasn’t familiar with this exotic material. By 1982, GIA’s Gems & Gemology publication reported a mere 10 specimens had turned up. Since this is truly a connoisseur’s stone, it’s hard to know exactly how many stones are in existence today – cloistered in private collections.
Thanks to today’s wealth of gemstone instruments, closer inspections into gemstone characteristics have become possible. John Bradshaw, co-owner Coast to Coast Rare Gemstones remarked about a Taaffeite he examined. “This particular stone was strongly fluorescent under LW-UV,” he pointed out, “it’s an unusual phenomenon for Taaffeite.” The stone’s trait was definitely an anomaly – in a species full of them. “It is the first time I have seen fluorescence in Taaffeite. The fluorescent stones all seem to be from Burma, at least so far,” Bradshaw reports. “The strength of fluorescence varies from light orange to strong red,” he tells us.
What Price Rarity?
How do you price something you never come across? Like more readily available gemstone counterparts, Taaffeite is valued by its colors, and the purity and saturation of its hues. So, a value range might be from $800 to $2,500 per carat for lighter stones. But for the finest Taaffeite colors possessing the coveted intense tones, it wouldn’t be unheard of to see a $15,000 per carat price tag.
Los Angeles based auctioneer Bonhams is known for selling world-class minerals to knowledgeable collectors with deep pockets. In their 2018 sale, they offered a kite shaped 5.34-ct lavender Taaffeite. When bidding stopped, it settled at $20,000 including buyer’s premiums. Not the highest price per carat, but a respectable amount given it was a light toned stone.
Eventually, more of these limpid stones will turn up in places we already recognize as a known source – and maybe even a few new deposits.
Modern gemology has come a long way since Count Taaffe stumbled upon his unusual ‘doubly-refractive spinel’ in Ireland nearly a century ago. But his perseverance and relentless quest for the right answers led to the discovery of a beautiful rare stone that carries his name forever.