The Vault, Natural History Museum, London

Mention precious gems at the Natural History Museum (NHM) and the chances are that people will recall the infamous Diamonds exhibition that was the subject of a speculative heist in 2005. In spite of it being closed three months prematurely, the museum is proud that its risk-management strategies are working.

It is therefore no surprise to learn that the head of security was a member of the team responsible for developing the latest display of rare gemstones, crystals, metals and meteorites housed in the Vault.

This is a permanent offering and security measures are obvious from the moment you approach the steel shutter marking the entrance to the gallery.

These are stones with stories. Each specimen is accompanied by an intriguing fact, and the language is full of superlatives. The objects are among the largest, finest, most spectacular and matchless examples in the world. We learn how they were discovered, who they are named after and why they are considered so valuable to science.

Many are shown in their natural state, chipped from the rock in which they originally formed and placed alongside cut and polished counterparts. A beautiful example is the deliciously named watermelon tourmaline, consisting of a cluster of crystal rods that radiate from pink to green. This is displayed beside a gemstone cut to show the two colours side by side.

This juxtaposition helps visitors to make the connection between natural resources and the objects that surround us. Part of the museum's mission is to encourage people to value the natural world and use it responsibly.

There is just enough text to intrigue, but not too much to overwhelm. Labels are clearly written and carefully positioned so as not to detract from the objects. The tone of the information is more cultural than scientific, in an attempt to appeal to a broader audience. Alan Hart, the exhibition curator, hopes the labels will inspire visitors to learn more. Brevity ensures they just give a flavour of the wealth of knowledge available on each object.

Scientists are continually discovering new things about these objects. Hart points out a meteorite that fell to Earth in 1911. For many years, it was believed to derive from the asteroid belt. However, tiny pockets of gas lodged in the surface of the object were recently analysed and compared with samples collected by space probes.

The meteorite was found to originate from Mars, a fact that caused a ripple of excitement in the scientific community. Hart wonders if it would be possible to discover a meteorite from Venus. (Highly unlikely because of the proximity of the planet to the Sun and the gravitational pull away from the Earth.)

These are the kinds of tantalising questions that motivate scientists to make new discoveries and which, no doubt, inspire many museum visitors to become scientists.

It is a perk of the job that allows people who work in museums to talk to people responsible for developing new exhibitions. For the public, this anomaly is addressed by an interpretive video that provides visitors with access to the specialists via a series of mini-interviews.

These films show the experts in their natural habitat, surrounded by heaving bookshelves and scientific instruments. While the concept is admirable, I found it difficult to enjoy. Directional speakers mean you must stand in a particular position to hear the soundtrack, yet this creates a bottleneck at busy periods.

Only one person, or two close friends, can listen at a time. People constantly squeeze by, obscuring the view and, most annoyingly, pushing the menu buttons that restart the film.

The Vault, as its name suggests, is a bijou room, not much bigger than a high street jewellery shop. Located at the far end of the Mineral Gallery, it replaces the Meteorite Pavilion, which is being relocated as part of a masterplan to upgrade the permanent displays. The design is bold and contemporary.

White walls, neutral flooring and the careful use of light give the room a space-age appearance, preventing the 85-sq metre room from feeling claustrophobic.

While many museums tend to show gems and precious stones in darkened spaces, the NHM has gone to the other extreme by displaying its collection in a bright environment. The inspiration for the design came from visiting some of the glamorous jewellery stores around London's Bond Street.

A row of wall-mounted showcases is reserved for highlights of the collection, with each containing a unique example. When the spectacular Star of South Africa diamond was unearthed in 1869, it sparked off a rush of digging by those hoping to find similar riches.

Now mounted in a 1910 Cartier pendant, the diamond sparkles and reflects like a miniature mirror ball. Clever lighting is one of the most important aspects of the display, ensuring each specimen appears to its best advantage. The Aurora Collection of rare coloured diamonds is particularly eye-catching.

Only one out of every 10,000 gem-quality diamonds is naturally coloured - and 296 are featured in the Vault. An alternating light source inside the showcase takes advantage of the fact that many of these gems glow or change colour when exposed to ultra-violet light.

Walking back through the Mineral Gallery that precedes the Vault takes longer than the inward journey. Although these old displays look tired in comparison to the new offering, visitors are stopping to look more closely at specimens they may have previously ignored.

The dodo carved into the 19th-century Alfred Waterhouse stonework of the gallery has never seemed so out of place. The NHM is alive and kicking and mineralogy rocks. Maria Blyzinsky is a freelance exhibitions consultant and a former head of exhibitions at the National Maritime Museum