Big Bling Thanks from the President-Elect to his First Lady

How, you might well have wondered, does a President-elect reward his first lady for putting up with two years of non-stop campaigning, and at least another four in the White House?

Well, now we know: he does it with a £20,000 piece of jewellery, crafted from the world's most expensive metal: rhodium. Rhodium?

The "Harmony" ring that Obama has ordered for his wife has been designed by the A-list Italian jewellery designer Giovanni Bosco, who's now busy knocking the thing into shape and encrusting it with diamonds before Inauguration Day rolls around on 20 January. Even dearer than those diamonds, however, will be the rhodium ring itself.

A hard metal from the platinum family, rhodium is mostly mined in South Africa and Russia, though only 25 tons of the stuff are extracted each year, most of which is put to work in aircraft spark plugs, precision optical instruments, LCD television screens and catalytic converters. Its typical worth is around £5,000 per ounce, hence the ring's estimated £20,000 price tag. Historically, when silver, gold and platinum simply didn't say "I love you", "Congratulations", or "I'm loaded" loud enough, rhodium has done the trick. Used in the world's most expensive pens and, indeed, to plate the Queen's crown jewels, rhodium was also the only metal sufficient to mark Paul McCartney's lifelong contribution to music. In 1979, the former Beatle was awarded a rhodium-plated disc by GuinnessWorld Records for being the bestselling songwriter and recording artist of all time. The Harmony ring, which Bosco's spokespeople call the company's "top of the range piece", is so sumptuous that even the jeweller will not disclose its true cost.

President-elect Obama's tastes are relatively restrained - he wears a functional watch, a simple wedding ring and sleek but unremarkable suits. His wife's sartorial success on the campaign trail wasn't achieved by spending big. In fact, her outfits are a solid mix of designer and off-the-rack, many found not on Fifth Avenue, but online at Jcrew.com. Not for Michelle the $70,000 outfits of Cindy McCain, nor the $150,000 shopping bills of Sarah Palin.

On the other hand, the First-Lady-in-waiting is not averse to a bit of bling, and has frequently been compared to that other White House style icon, Jackie Kennedy, whose jewellery continues to inspire knock-off collections to this day. (Fancy the look of a Jacqueline Kennedy Wedding Bracelet featuring 18 Simulated Pearls, 25 Swarovski Crystals and platinum plating? That'll be $99, thank you very much).

Michelle has occasionally invoked the style of Jackie with a string of faux pearls, made her distinctive brooches a staple of her public appearances and, on election night, complemented her controversial Narciso Rodriguez dress with diamond drop earrings and glittering silver bangles.

The rhodium ring, a gift truly fit for a First Lady, will make an impressive addition to her jewellery box.