Stolen jewelry, now on display

For six months, a team from the British Museum worked with police to recover hundreds of engraved gemstones and other jewelry that museum officials say were stolen from the storerooms by a former curator.

The team has also planned an exhibition.

“Rediscovering gemstones”, which occupied a room near the grand entrance of the British Museum until June 2, contains dozens of small artefacts known as cameos and intaglios – 10 of which are recovered objects.

Art dealers who bought the stolen objects – some of which date back to ancient Rome – have so far returned 357 treasures to the museum, said Aurélia Masson-Berghoff, a curator leading the recovery team.

Although more than 1,000 items are still missing and it could take years to locate them, Masson-Berghoff said her team was hopeful those could be recovered as well. The new exhibit was part of the museum's efforts to be transparent about the thefts and efforts to retrieve the items, she added.

During a recent tour of the exhibition, Claudia Wagner, the museum's lead researcher on gemstones, said the jewels had long been undervalued. The small artifacts – often less than a centimeter in size – are difficult to distinguish in natural light, making them easy to ignore, she added. There are small torches in the exhibition hall so that visitors can see them clearly.

Some of the museum's former Greek and Roman curators had preferred to focus on larger and better-known objects such as statues and vases, Wagner said, which could explain why many of the cameos and intaglio prints were not in the catalog before the thefts.

During the tour of the exhibition, Wagner and Masson-Berghoff discussed the origins of these precious gemstones, their use in ancient times and how they once captivated European art connoisseurs. These are edited excerpts of that conversation.

WAGNER The first engraved gemstones were so-called intaglios, where the design was cut into the gemstone or glass. They were used as seals, so people pressed them into wet clay – the equivalent of writing your signature.

They were invented in Mesopotamia, but it was the ancient Greeks who turned them into their own art form, and because the Greeks were so interested in mythology, all the gods are represented right away. If you look very, very closely at this little figure, he has a wreath of ivy in his hair. That's because this is Bacchus, the god of wine.

The gemstone is so small – only an inch or two – because you wore it as a ring.

Glass cameo depicting a winged Cupid

WAGNER In addition to intaglio printing, there are cameos, where the design is carved in relief. This is a pretty good one of Cupid: a sweet boy with wings. Many of them were gifts, and when you look at this you still feel like it was for a dear lover.

Cameos and intaglios were first engraved on gemstones. The Romans did not learn how to make glass gemstones until the first century AD. Glass was new and exciting to them and it meant you could mass produce these objects. It was still a very complicated and difficult process to melt glass in a mold, and you see many glass gemstones set in very expensive gold frames.

Glass cameos with images of the Three Graces and a sea nymph

WAGNER During the Renaissance, people became completely obsessed with carved gemstones because everyone looked back on how great the classical artists were.

Collectors also liked gemstones because they were undamaged. If they bought a classic statue, it would be missing its arms or its nose. But these cameos were complete, so collectors saw the image as the Greeks and Romans did. None of these gemstones were stolen or recovered – unlike the other items – but they are included in the exhibition to show the beauty of the small images, and the difficulties involved in creating these masterpieces in glass.

MASSON-BERGHOFF Michelangelo is said to have copied a cameo from Augustus and used it in his design for Adam in the Sistine Chapel. His Adam has the same pose. The craze for gemstones really started in the Renaissance.

WAGNER In the 18th century, collectors who went on a Grand Tour of Europe also became fascinated by antiquity, and some became huge gem collectors.

Because so many people tried to buy these items, engravers began making many counterfeits. It was a huge scandal because suddenly everyone thought, 'We can no longer distinguish between what is old and what is new.'

This cameo is fake. We have no idea who it is for. Usually they are intellectuals, but you can see that this is not entirely correct: he is not one of the great philosophers you might recognize from antiquity. And the texture is also different from other cameos: it is much smoother.

With the help of our chemists, we can now distinguish what is Roman glass and what is not.

WAGNER These gemstones are very difficult to display because they are so small. This one is barely two centimeters long. We have a huge copy of this on the wall in the exhibition, so people can see all the details clearly. It radiates its beauty.