The Arcot diamonds were at one time in the collection of Queen Charlotte mounted as earrings. HM left instructions that the diamonds were to be sold and the proceeds divided among her daughters. George IV delayed implementing that part of her will for a long time, but eventually they were sold and came into the possession of the jewellers Rundell and Bridge. After the death of the latter the Arcots were again sold, this time to Emanuel Brothers who were acting for the then Marquis of Westminster. A later Duke had the stones set in an extraordinary tiara. The rest of the provenance is given in Christie's details.

https://www.christies.com/lotfinder/jewelry/the-arcot-ii-6211836-details.aspx?from=salesummery&intobjectid=6211836&sid=6d4148a6-3e86-4351-bd52-264836eca2cf


1937 auction


The Arcots are the earrings described in item number 12.