The Aquamarine Necklace Tiara is thought to be part of Sophie’s private jewellery collection.
But Sophie has also worn another aquamarine tiara featuring five big stones thought to be from the late Queen’s collection.
The Countess was pictured wearing the stunning diadem at the wedding of Princess Madeleine of Sweden and Christopher O’Neill in 2013.
According to MyLondon, experts have estimated that the Queen’s Brazillian parure is worth in excess of £5million.
In comparison, the Five Aquamarine Tiara that Sophie borrowed from the Queen is reportedly worth £1million. Sophie’s Aquamarine Necklace Tiara is worth approximately £500,000.
Adding to her catalogue of aquamarine jewels, Sophie also frequently dons a brooch and a statement ring featuring the stone.