Superhard materials

“Initial experiments where metallurgical coke was converted into graphene resulted in a material that appeared similar in size to sand”

The largest ruby in the world will be offered by Sotheby's in New York in June, the auction house said at a preview in Hong Kong on Apr 17, and is estimated to fetch more than US$30 million.

A rare rough ruby dubbed one of the world's biggest has gone on display for the first time ahead of an auction in the Gulf emirate of Dubai.

The 8,400-carat stone, nicknamed Burj Alhamal and weighing 2.8 kilograms, was mined in Tanzania and made its debut at a Dubai hotel on Friday as part of SJ Gold and Diamond's Callisto collection.

A sapphire-and-diamond brooch and matching ear clips which once belonged to Russia's Romanov imperial dynasty were snapped up at a Sotheby's auction on Nov. 10 for nearly $900,000.

A jewelry set worn by French emperor Napoleon Bonaparte's adopted daughter sold for $1.65 million in Geneva on May 12, soaring way above the pre-auction estimate.

Marking the 200th anniversary of Napoleon's death, Christie's auction house sold the nine imperial jewels adorned with sapphires and diamonds, which were from the collection of his adopted daughter Stephanie de Beauharnais.

Victoria’s Secret Fantasy bras, which are worth $2m, have gone on display at Singapore JewelFest, where exquisite goods from more than 42 Asian designers are displayed.

The iconic bras were designed by Mouawad jewellers and took more than 1,380 hours to make using 16,000 rubies, diamonds and sapphires.