Among the wedding gifts which Lord Rosebery gave to Hannah de Rothschild when they married in March 1878 was a sapphire and diamond pendant with a large pearl drop. In a number of the reports the large sapphire is described as being "deep" coloured. Unless the photos OmerH found and the one in the newspaper are misleading the so called "Rosebery jewel" has a very deep blue sapphire.

On the other hand the stone might have been purchased in Ceylon (as the press reports indicate) when Lord and Lady Rosebery travelled to India from November 1886 to February 1887.