The Paraiba Tourmaline Phenomenon

It looks like Christie's pitched a little low. Their pre-sale estimate for a 13.54-carat Paraiba tourmaline was just $400,000 to $600,000. It sold at their New York Magnificent Jewels auction last week for $4,223,000.

So what's the story with Paraiba tourmalines, and why do they command such astonishingly high prices?

Regular tourmaline is no big deal. Hundreds of tonnes of it are mined every year across Brazil, Afghanistan, Madagascar, Nigeria, Mozambique, Sri Lanka, Pakistan, and the USA, mostly for industrial use.

A small fraction - a few million carats - are gem quality, mostly pink, green, and watermelon, although examples exist in pretty much every color of the spectrum.

Tourmaline was recognized as a distinct mineral species back in the mid-1700s. But it was only in 1989 that vivid blue-green gems, with a distinctive neon glow, were discovered.

Pic, courtesy Christie's, shows the 13.54-carat Paraiba tourmaline, with a matching pair of earrings that sold for $1.3m (estimate $250,000 to $350,000). 

They caused a sensation. The intensity and saturation, a result of copper traces in the crystal structure, were beyond eye-catching. When they first hit the market there was near hysteria.

At the opening session of the Tucson Gem and Mineral Show in 1990, the first Paraiba tourmalines were reportedly selling for $200 to $300 per carat. Days later, as the show closed, they were changing hands for as much as $3,000 a carat.

They weren't just a thing of beauty. They were, and still are, exceptionally rare.

It was a prospector named Heitor Dimas Barbosa who discovered Paraiba tourmalines near the village of Sao Jose da Batalha in Paraiba State, northeastern Brazil.

He was working old mines that had previously yielded aquamarine, topaz, and ordinary tourmaline when he found this never-before-seen neon variety.

Tiffany & Co. saw an opportunity and bought up much of the best-quality Paraiba rough directly from dealers who had acquired it from Barbosa and local miners.

Prices kept soaring, typically to $10,000+ per carat for the best AAA examples (neon, vivid, glowing color, pure and intense). Grading is much like the 4Cs, but with a heavy emphasis on color.

And then, within a decade, the Paraiba mines were exhausted. Miners using picks, chisels, and hammers had extracted all they could.

There were just a handful of "mines," and each was essentially a single pegmatite (igneous rock formed from the late-stage fluids of cooling magma) or a few veins, sometimes just a few meters wide.

Miners focused on visible pockets containing copper-bearing neon-blue tourmaline crystals. A pocket would typically yield a few hundred carats at most.

That means the total number of carats ever mined is measured in tens of thousands. For context, 118 million carats of rough diamonds were recovered in 2024.

So it's not hard to see why Paraiba tourmalines are highly prized. But that still doesn't explain why the winning bid last week was 10 times the low estimate.

Part of the answer is that auction houses can be overly conservative with their estimates, to avoid the embarrassment of unsold lots.

But there are other factors at play. Only a tiny number of large Paraiba tourmalines have ever appeared at auction, so there's little in the way of historical guidance.

The largest polished Paraiba tourmaline in existence - the 191.87-carat Ethereal Carolina Divine Paraiba - was valued at somewhere between $25 million and $125 million when it was unveiled in 2009.

The huge range shows just how difficult it is to gauge the value of such a rare gemstone.

Size definitely matters for Paraibas. Experts would typically expect a 1.0-ct Paraiba to sell for $10,000 to $15,000 per carat. A 10-ct+ stone could fetch $30,000 to $60,000 per carat. (Christie's low estimate actually equates more or less to that $30,000-per-carat valuation.)

But then there's emotion. The bidding frenzy. And an overwhelming desire to be the owner of the world's most valuable Paraiba. Whatever the cost.

Have a fabulous weekend.