This beautiful brooch comprises of rose cut natural white zircons, called Matara diamonds also called jargoons, set in a foliate design surrounding a gilt set blue stone flower.  This 19th century brooch has parallels with eighteenth century European jewellery, albeit with South Asian motifs. Length 7 cms, width 3.5 cms. It looks as if there is some brown discolouration on some of the diamonds but I have been able to clean it off, it was on the surface.
These brooches were used in place of buttons to keep blouses closed. 
Examples can be found in National Museum of Sri Lanka, Colombo.