Kate Middleton Engagement Ring Once Belonged To Princess Diana

If soon-to-be Princess of Wales Kate Middleton’s engagement sparkler looks familiar, it should: Prince William has given fiancee Kate Middleton the engagement ring that belonged to his late mother, Princess Diana.

The blue sapphire and diamond ring was given to Diana by William’s father, Prince Charles, when they became engaged in Feb. 1981. The ring is an oval blue 18-carat sapphire surrounded by 14 smaller white diamonds. Thirty years ago, the jewel cost about $65,000. Today, the same ring would likely retail for about $150,000, according to appraisers.

On Tuesday, William announced that after an on-off courtship that has lasted nearly a decade, he is set is to marry his college sweetheart Kate Middleton in a royal wedding ceremony in London sometime in mid-2011. The British royal popped the question to Middleton during a vacation to Kenya in October. The nups will give Britain its biggest royal wedding since Charles married Diana nearly 30 years ago.

Lady-in-Waiting Middleton showed off her engagement ring as she and fiance William posed for photographers during a photocall at St. James’ Palace in central London.

“It is very special to me,” William explained of why he chose to pop the question with Princess Di’s ring. “It was my way to make sure my mother did not miss out on today and the excitement that we are going to spend the rest of our lives together.”