DETAILS: Kate Middleton's Wedding Band

Jan Springer, an advisor to the World Gold Council, leaked details on Kate Middleton's wedding band made from some of the rarest gold in the world.

Prince William presented Princess Diana's engagement ring to his future bride when he proposed in October, but the princess-to-be will have a wedding band all her own.

Jan says that we can expect Kate to wear an 18 carat, Welsh gold ring. Welsh gold is six times more valuable than other types of gold and 18 carat means that the ring will be three quarters pure.

"The color of it is slightly more rosy," Jan told us at London's Goldsmith's Hall. "We don't have that much Welsh gold left and the nuggets [are] firmly under lock and key."

A spokeswoman at the Palace has confirmed that The Queen has donated a family supply of Welsh gold to crown jeweler, Harry Collins, to create Kate's wedding band.

Other
members of the Royal Family that have worn pure Clogau Welsh gold
wedding rings include Princess Margaret The Countess of Snowdon (1960),
Princess Anne The Princess Royal (1973), Diana The Princess of Wales
(1981), Prince Charles (1981) and most recently Their Royal Highnesses
The Prince of Wales and The Duchess of Cornwall (2005).

Click the video to see what wedding bands looked like in the seventh century.