Taaffeite: Why It's So Rare, What It Costs, and How to Tell It From Spinel

Most cut taaffeite is listed between $1,000 and $3,000 per carat. Stones of 3 carats and more with a report from a major laboratory are asked $3,000 to $10,700 per carat. Here is what three sellers showed on 7 October 2026, in US dollars.

These are asking prices, not sale prices. In these listings, the highest asks go to stones of 3 carats and more that carry a report from a major laboratory. On colour, purple is the most appreciated.

For scale, the purple spinel it resembles is asked about $70 to $900 per carat at three sellers. See our spinel price per carat page, and our colored gemstone market statistics for the wider picture.

Not by eye. The two share the same pinks and purples, and their refractive index and density overlap. One property separates them: taaffeite is doubly refractive, spinel is singly refractive.

That is how the first one was caught. In 1945, Richard Taaffe found it in a jeweller's shop in Dublin, already cut, offered to him as a spinel. Taaffeite is still the only mineral first discovered as a faceted gem.

1. Polariscope. Turned between crossed filters, a spinel stays dark. A taaffeite blinks from light to dark.
2. Refractometer. Taaffeite reads 1.719 to 1.723, with a birefringence of 0.004 to 0.005. Spinel reads around 1.718, with none.
3. Laboratory. Musgravite, the closest relative of taaffeite, has overlapping properties. Only Raman spectroscopy or X-ray diffraction separates the two.

Try the first test yourself:

Two traps with the polariscope. Seen down its optic axis, a doubly refractive stone also stays dark, so it has to be tilted and turned again. And some singly refractive stones, synthetic spinel above all, show moving bands of shadow that can pass for blinking. A bench test narrows it down. It does not name the stone.

Yellow is not in the usual colour range. Taaffeite runs from pink to red and purple, also blue, violet, brown, greenish grey and colourless.

Yet stones are sold under that name. We found three listings: a 0.55 carat stone from Mogok, described by its seller as very pale yellow, almost colourless, a 1.36 carat yellow stone from Myanmar, and a 1.60 carat yellow stone from Tanzania.

So a yellow taaffeite can be offered to you, and the one seller who describes the colour closely calls it almost colourless. The name alone proves nothing. Before you pay, ask for a report from an independent outside laboratory that names taaffeite. Our guide explains what a gemstone certificate proves.

Very rare, and typically very small. Of the 33 listings we counted, 23 weighed 2.5 carats or less. Gem-quality stones come from four places:

• Sri Lanka: where the first rough fragments turned up, long after the first cut stone.
• Myanmar: Chaunggyi, a few kilometres north-west of Mogok.
• Tanzania.
• Madagascar.

Keep those sizes in mind when you shop. Be wary of a very large stone offered as taaffeite. A stone that size needs a laboratory report before it needs a buyer.

My view: decide what you are paying for.

• The rarity. Buy taaffeite only with a report from an independent outside laboratory that names it, and expect a small stone.
• The colour. Purple spinel gives you a similar violet at 8 on the Mohs scale, with good toughness. Spinel is rarely treated, and purple is one of its less sought-after colours, which keeps the price down.

Here are six purple spinels from our stock, ranked by the colour saturation measured on each photo:

We do not stock taaffeite, and I would rather say so than take a deposit on a maybe. What we do have is loose purple spinel, chosen one stone at a time. A report from an independent outside laboratory can follow your purchase. To go further, read our guide to spinel.