The sentimentality is increased by the fact the necklace was given to the Queen Mother by her husband, the Queen’s father, King George VI in 1937.
It was given to mark their coronation as King and Queen, an event they never foresaw as it came after the abdication of King George’s older brother.
The Queen Mother wore it for the coronation, and at the time it contained 40 very large diamonds.
The and piece has continued to be worn at important events throughout recent royal history.
READ MORE: Incredibly important piece of jewellery the Queen gave to Kate Middleton
This type of necklace is known as a collet necklace. It is made of single diamonds in a row and is a simple piece although stunning and valuable.
The Queen has many of these types of necklace including Queen Alexandra’s collet necklace and the Duchess of Teck’s collet necklace.
Charles and his second wife married in 2005 and since she has worn a lot of royal jewellery.
This includes a piece of jewellery she wears the most, her engagement ring.
However, it has been suggested recently Princess Diana’s engagement ring is now worth more than the Duchess of Cornwall’s.
Diana, famously, was given a sapphire and diamond ring from Prince Charles on their engagement.
A new study by jewellery retailers EST1897 has analysed the most expensive engagement rings of all time.
Kate’s oval cut sapphire ring is perhaps the most iconic royal engagement ring and is also the most expensive, this report claims.
Purchased for £28,000 in 1981, the ring is now said to be worth £390,000.