The lexicon of gem colours

When a colour has a name, it has a price

The gem world has named its most sought-after hues, and these names are not idle poetry: they designate precise shades worth fortunes. Knowing them means understanding dealers' labels — and knowing when a seller is exaggerating.

The legendary colours

“Pigeon's blood” denotes the pure, very slightly bluish red of Burmese rubies from the Mogok valley. It is the costliest colour in the mineral kingdom, and the term is now so coveted that laboratories have had to define it precisely to prevent abuse.

“Cornflower blue” denotes the velvety, luminous, slightly milky blue of Kashmir sapphires, whose mines — exhausted for a century — made the legend. “Padparadscha” — “lotus flower” in Sinhalese — is the pink-orange sapphire the colour of dawn, one of the most sought-after gems in the world and one of the rare ones whose name is protected.

“Paraíba” is a case apart: this electric neon blue-green of copper-bearing tourmalines, discovered in Brazil in 1989, caused an earthquake in the gemmological world. The hue is so spectacular that it was first assumed to be a treatment.

Marketing names, and the ones that mislead

Brown diamonds, long shunned and sold cheaply, were rebranded “cognac” and “champagne” — a stroke of commercial genius that turned them into objects of desire. “Canary” denotes the vivid saturated yellow of fancy vivid yellow diamonds.

The word “imperial” serves two purposes: imperial topaz, the pink-orange of the Russian tsars, and imperial jade, the translucent emerald green that is the most precious variety in the world. Beware, on the other hand, of fanciful names with no basis: if a name appears in no mineralogy text, be suspicious.