A ruby offered at auction and a laboratory-grown ruby are the same mineral: corundum, coloured red by chromium, nine on the Mohs scale of hardness. The difference lies in where each was made and what it carries with it. A ruby from the earth is valued for its origin, its untouched state and its rarity; a laboratory-grown ruby is valued for its colour, its clarity and the scale at which it can be worn.
A ruby from the earth
This season Sotheby’s offers, in its High Jewelry sale, an important ruby ring set with a cushion-shaped stone of 16.51 carats, estimated at 220,000 to 380,000 Swiss francs. It comes with three laboratory reports, two from the Swiss Gemmological Institute and one from Gübelin, and all three record no indications of heating. The laboratories differ on its birthplace: two name Vietnam, home of the Luc Yen deposits, and one names Afghanistan. All agree on its quality, and the Swiss Gemmological Institute has issued a special appendix calling it an “exceptional ruby”. A stone like this is valued for everything the earth gave it: its origin, its untreated colour and the rarity of finding a ruby so clean at such a size.
A ruby grown above ground
A laboratory-grown ruby is corundum too, with the same chemistry, the same crystal structure and the same hardness as a ruby from the earth. It takes the same polish and holds the same red by daylight and candlelight. Grown, a ruby can be cut for colour and presence first, so that a stone of sixteen carats, saturated and bright from edge to edge, becomes a ring to wear rather than a lot to bid on.
The Empress Ruby, sixteen carats, in hallmarked platinum.
The Empress Ruby
The Empress Ruby was the first piece of The Bardot Collection: sixteen carats of pigeon blood red, pear-cut and measuring twenty by twelve by nine millimetres. A double gallery claw in hallmarked platinum holds the stone with the least possible interruption, and a knife-edge shank, three millimetres at its finest, lets the hand frame the ruby. It is also made in eighteen-carat gold. Each ring is made individually in Britain, sized to the wearer, and assessed by a jeweller qualified with the Gemological Institute of America and the Gemmological Association of Great Britain, with authentication and valuation documentation included.
At a glance
The auction ruby: 16.51 carats, cushion shape, formed in the earth, origin given as Vietnam or Afghanistan, no indications of heating, estimate 220,000 to 380,000 Swiss francs.
The Empress Ruby: 16 carats, pear shape, laboratory-grown, pigeon blood red, hallmarked platinum or eighteen-carat gold, made individually in Britain.
Both: ruby, the red variety of corundum, nine on the Mohs scale.
Sixteen carats, one for every year: A Carat for Every Year.
The Empress Ruby is shown in detail by private video appointment, from wherever you are in the world.
