Kate will never wear most expensive royal jewel but donned £66m piece

Experts at Cashfloat revealed the most valuable pieces of jewellery in the Royal Family collection.

The Imperial State Crown, a breathtaking headpiece made of gold and an impressive array of gems, is only worn by the King or Queen during their Coronation at Westminster Abbey.

The majestic jewel features 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls and four rubies.

Kate, Princess of Wales will never wear the incredible piece of jewellery as it is reserved for the reigning Queen or King, so Prince William will be the next one to use it.

However, the Princess of Wales did wear the second most expensive jewel in the royal collection, the Nizam of Hyderabad Necklace.

The necklace, which was a wedding present from the Nizam of Hyderabad, has an estimated value of £66.3million.

In 1947, five years before she became Queen, Elizabeth was given the Nizam of Hyderabad Necklace as a gift for her engagement to Philip Mountbatten.

The experts explained: “This lavish necklace, with over 50 diamonds set in platinum, has been featured in multiple portraits of the late Queen prior to her Coronation and has even been loaned to the Princess of Wales multiple times in recent years.”

The Nizam of Hyderabad necklace was worn by Kate for the first time in 2014 at an event at the National Portrait Gallery, in London.

The Princess of Wales looked stunning donning the sparkling jewel which she paired with a navy blue Jenny Packham gown.

Other valuable pieces of royal jewellery include the Delhi Durbar Emerald Choker (£16million), “one of the late Queen’s most distinguished and precious possessions”.

The Greville Emerald Kokoshnik Tiara (£10million) is another expensive piece, and the late Queen decided to loan this extravagant piece to Princess Eugenie for her wedding day, making it an iconic “something borrowed”.

The diamond and emerald diadem, crafted by the French jeweller Boucheron, has been around for nearly 100 years but “it has only been part of the Royal Family for a little over 75 of those”.

The experts explained: “Initially belonging to Dame Margaret Greville, the tiara was bequeathed to the Queen Mother upon Greville’s death and the royal collection was then passed on to Queen Elizabeth after the Queen Mother’s passing.”