The empty gold frame and its aquamarine monde which dates from the reign of King James II are both part of the Crown Jewels of the United Kingdom.

[1] The crown is vibrantly depicted in a watercolour painting by Bernard Lens III, the miniature painter to the court of George II, dated 1731.

This date suggests that Lens had made a sketch of the crown before it was entirely reset in 1727 for George II but did not finish it until some time afterwards.

The ornaments are silver and set with diamonds; the larger stones are sapphires and emeralds, and a few small rubies.

[6] The "aquamarine" dates from 1685, when it replaced the original monde in the state crown of Charles II, and was later found to be paste or coloured glass.

In 1821, because it was seen as being a "very poor affair", the crown underwent extensive changes, including the replacement of the rhombus-shaped monde with a globe of diamonds.