A blue diamond ring that once belonged to child star Shirley Temple is up for auction at Sotheby's on April 19.

It's valued at $25m-35m, substantially more than the $7,210 (around $122,000 after inflation) Temple's father paid for it in 1940.

Shirley Temple was a huge star during the 1930s

Frank Everett, Sotheby's head of jewellery sales, comments: "Shirley Temple helped to lift America's spirits out of the Great Depression, and served her country in many capacities throughout the remainder of her life.

"Her ring and its original Art Deco setting recall a time when she was nothing short of the biggest movie star in the world."

Sotheby's will also offer the De Beers Millennium Jewel 4 in a Hong Kong jewellery sale on April 5, which is valued at $35m.

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