It was a house record for jewellery.
Offered in its original fitted box, it had been housed in a safe for 40 years and was on the market for the first time since it was bought by a descendant of the vendor c.1860.
An unusual feature saw the 18 principal stones (there are 42 in total weighing over 50 carats) mounted in settings engraved with their old grain weights.
The largest stone is around five carats.
The buyer's premium at the sale on December 6 was 22%.