Jewellery, Watches and Objects of Vertu to include the personal archive of Louis Osman, goldsmith and architect

A 19th century diamond cross brooch, the Latin cross with flared arms composed of graduated pinched collet set old brilliant-cut diamonds between graduated cushion-shaped old-cut diamond borders, around a central old brilliant-cut diamond cluster, mounted in gold and silver, brooch length 37mm. £1500-2000