It was the film that was begging to be made - Elizabeth Taylor’s extraordinary life is explored through the auction of her iconic jewellery collection in Channel 4’s must-view documentary Elizabeth Taylor: Auction of a Lifetime.

The feature, set to air tonight (18 April) at 9pm, centres on Christie’s landmark Elizabeth Taylor Collection auction last December, where frenetic bidders shifted over £74 million in a single night, making it the most valuable private collection of jewels to ever sell at auction.

Not only is the actress's love affair with jewellery examined, the people central to her life are also explored with exclusive interviews with Joan Collins, Liza Minnelli, Mickey Rooney and designers like Bulgari, Cartier and Valentino.

So, in the spirit of Liz’s "Crown Jewels of Hollywood," we’ve trawled the archives to find the five most expensive gems ever to have sold at auction...

Words: Sejal Kapadia. Picture Credit: Rex Features, Channel 4

1. The Graff Pink – sold for £28.9 million

Holding the world record for the most expensive diamond and jewel ever sold at auction, this diamond is as extraordinary as it gets. The pink toned rectangular stone weighs 24.78 carats and is set between shield-shaped diamond shoulders, in platinum. Formerly owned by diamond giant Harry Winston, Laurence Graff bought it at Sotheby’s, Geneva in 2010 and rebranded it its current title.

ABOVE: The Graff Pink ring, which sold for almost £29 million.

2. The Wittelsbach-Graff Diamond - sold for £16.4 million

This historic cushion cut grey-blue 35.56 carat diamond originates from the ancient Indian kingdom of Golkonda. Laurence Graff purchased the diamond at a Christie’s London auction in 2008 and controversially had it cut by three different diamond cutters to remove every flaw in 2010.

3. The Perfect Pink - sold for £14.86 million

It’s all in the name. Christie’s 2010 auction in Hong Kong became a rare event in the world of jewels, where in over 244 years of auction history this was the first to be graded a ‘Fancy Intense Pink’. Cut to a rectangular shape at 14.23 carats, the stone is considered perfection amongst gem connoisseurs worldwide. Sadly it sold to an anonymous buyer.

ABOVE: The Wittelsbach-Graff Diamond, worth a cool £16.4 million.

4. The Bulgari Blue - sold for £9.94 million

This two-stone ring was designed by the house of Bulgari in the 1970s, and features a triangular blue diamond, the largest ‘Fancy Vivid Blue’ diamond of this cut to ever be offered at auction. It was purchased by an Asian collector in a three-way bidding battle.

ABOVE: Liz Taylor wears the famous La Peregrina necklace in 1992.

5. La Peregrina – sold for £7.6 million

Featured in the documentary, this diamond, pearl and ruby necklace holds a 500-year-old pearl drop, originating from the crown jewels of Spain. Once owned by Mary Tudor, Richard Burton famously purchased it for Taylor as a Valentine’s gift at $37,000 in 1969, after successfully outbidding a member of the Spanish Royal family. Today, it holds the World Auction Record for a Pearl Jewel.

Above: Stills from Elizabeth Taylor: Auction of a Lifetime, airing tonight on Channel 4