Art: On the rocks

    Yes, they twinkle, they enchant, they delight, you give them to people you love, they are sensationally exciting to look at, scientists drill tough things with them, and it seems their scientific importance is growing. But they also make terrible mischief wherever they appear, and always will. Would the world be a better and safer place without diamonds? Unquestionably. Would there be less corruption, misery, exploitation, exhaustion, pollution, dictators, bad government, heartache, a lot less divorce? Yes, yes, yes. Do I regret the arrival at the Natural History Museum of the largest display of high-grade diamonds ever assembled? Are you kidding? Bring on the biggest first — they sparkle the most.

    The thing about diamonds is that they give you something nothing else can. When a flashing diamond hits its mark, something deep within our human hard-wiring responds with goose bumps and surges of serotonin. My private theory is that the attraction of diamonds has to do with their superficial resemblance to a star-filled sky. It is a prehistoric thrill. But I am no Newton, and that is just guesswork. Whatever it is, it only works if the conditions are right. Diamonds may be the hardest substance known to man, but their beauty is spectacularly fragile.

    Which is why the Natural History Museum has failed us so miserably, with a chaotic and frantic display that seems more concerned with expanding the engagement-ring market than with understanding the true magic of diamonds. This chronic misjudgment of mood begins at the opening queue ramp, where a pumped-up video sets about comparing the instant glamour of assorted starlets and models with the rocks they flaunt. On the catwalk, at the Oscar ceremony, around the neck of Scarlett Johansson, between the breasts of Helen Mirren, every fast-cut diamond in the montage manages to look exactly like all its predecessors: a clip-on flashing effect that lights up its wearer quickly and gaudily. I doubt that the intention of this crass opening video was to make diamonds appear mass-produced and essentially characterless, but that, certainly, is what is achieved.

    The show that follows is always short of classy silences and always long on cheap and loud effects. While it is undoubtedly true that diamonds have the ability to discover some Posh and Becks in even the noblest royal bloodline, did it really need to be proved so incontrovertibly? See what Frederik Augustus III gave his queen in 1782: a huge silver bow made from 662 diamonds, weighing a combined total of 614 carats. Huge silver bows work perfectly well as cake decorations, but nothing you do to them as jewellery can turn them into a serious enough shape for which to sacrifice this many exquisite brilliants.

    The finest stones have cabinets to themselves, and some lighting, which is all a good diamond has ever needed. But the rest of the show has been manically divided and sub- divided into a confusing melange of themes and topics that flashes on and off as noisily as a pachinko parlour in downtown Tokyo. There is stuff here about the most famous diamonds in history, and about what one celebrity gave to another. There is a tiara worn by Catherine Zeta-Jones at her wedding to Michael Douglas, and a portrait of the rapper Usher picked out in yellow diamonds on a watch dial, a piece of bling that badly needs banging with a hammer. There is stuff about the origins of diamonds and how they are cut, all delivered to the accompaniment of electronic throbs and bleeps that destroy the hush and attack every diamond’s innate sense of preciousness. It is a heist, really. What has been stolen is the diamond’s true spirit.

    The problem is, of course, that diamonds are such tiny things in the flesh, even the biggest of them. Without the starlets and the flashing late-night pinball-table effects, without the Oscar footage and the boxing-ring entrance music, this entire show would fit easily into a small handbag. It consists of almost nothing. And it is the process of enlarging it with obvious things to see that has led to the worst of the decision-making.

    In these inglorious circumstances, it takes a special diamond to emerge with glory, and fortunately there are several here. We have, for instance, the Indian table-cut worn as a turban ornament in 1616 by Shah Jahan, whose sense of preciousness was so expandible that he also gave us the world’s most beautiful building, the Taj Mahal, a diamond-like experience attempted across three giant architectural dimensions.

    Most of the diamonds on show are diamond-coloured, which is to say, uncoloured, unstoppable fountains of sparkling white light that seem always to be on the move, even when the diamond is still. But the exhibition has as one of its stated aims the highlighting of the beauty of coloured diamonds, which can be pink, yellow, blue. So, while the awesome De Beers Millennium Star (the world’s unluckiest uncoloured diamond as well as one of the largest, it would seem, fated for ever to appear in shoddy circumstances: this, you may remember, was the diamond someone tried to steal from the Millennium Dome) is positioned near the start, it is preceded by a rare assortment of utterly gorgeous fancy-coloured gems.

    The Moussaieff Red is a triangle of deep, light-scattering crimson from Brazil, so unusual that the Gemological Institute of America, called in to settle its authenticity, admitted to never having seen a diamond of this colour before. Who has? Paler than a ruby, with so much more explosive flashing ability, it is small by big diamond standards — “only” 5.11 carats — but, like all truly great diamonds, acts as a tiny doorway into a bigger experience and leaves you feeling as if you are peeping through a small hole into a huge furnace.

    The same is true of the Orange Flame, 3.23 carats of mineral masterpiece from South Africa that manages to combine the intensity of a marigold with the crystalline rush of a mountain stream. And, of course, nothing could ever seriously diminish the beauty of the Steinmetz Pink, 59.60 carats of frosted camellia, unveiled, I seem to remember, at the Monaco Grand Prix a few years ago, where it set the pulse racing far more quickly than any of the cars.

    These astonishing gems are easily worth the entry fee on their own. The show they are in doesn’t deserve them.