Victorian diamond & pearl star brooch

A refined mid-19th century six angle star shaped brooch. The enamel and diamond brooch is centred with a 6,5 mm half pearl and set with 18 Old mine cut diamonds. The half white Akoya pearl can be detached and could have originally been replaced with a big  centre stone, Multifunctional jewellery like this was quite popular in de mid 19th century. This centre stone probably also served as part of other jewellery like a tiara. The current pearl is the original centre when not using the described centre stone. 
Estimated total diamond weight 0.50 ct measurements. Measurements 38 x 28 mm.