A gold and enamel desk seal, possibly English or French, second quarter of the 19th century

A gold and enamel desk seal, possibly English or French, second quarter of the 19th century 

the spherical top decorated with leaves and petals in translucent green, dark blue, turquoise and orange basse taille enamel in 17th century cosses de pois style, around an opaque white enamel centre in high relief, resting on a baluster stem, the circular spreading foot applied with the Stuart coats of arms (the arms used by the Stuart monarchs of England and Scotland between 1603 and 1714) in champlevé enamel, the rock crystal matrix engraved with the arms of the Ponsonbys, Earls of Bessborough, possibly the 5th Earl of Bessborough, apparently unmarked, in a modern green leather case, 

5.5cm., 2¼in.