Antique Edwardian old cut diamond and opal cluster brooch 15 carat gold

Era: Edwardian 1901-1910
Metal: 15 carat gold and platinum, stamped
Gemstones: old cut diamond 4.98x4.68mm, rose cut diamonds x12, opals x12
Weight: 6.9g
Size: 18mm diameter cluster, 63mm long bar
 
A delightful bar brooch, crafted in 15 carat gold and platinum, dating to the early 20th century. The focus of the piece is the large central cluster, formed of three layers, an outer ring of clear based 'jelly' opals, theses encircle a ring of rose cut diamonds and to the centre is a large old cut diamond. The gemstone settings all have crisp millgrain details, so typical of this period of jewellery design and the whole piece has clearly been created by a master, as the work is exemplary.
 
The diamond in the centre has a very symmetrical cut and smaller cullet, more reminiscent of an OEC than an old mine cut, however the shape is square with rounded corners, so I would refer to it as an old cushion cut. It has a hint of warmth to the colour, but this may pull from the yellow gold bar that passes behind it at present. It is eye clean and bright.
 
This would make a fantastic pendant in my opinion, by removing the bar and adding an 18ct gold or platinum jump ring to the central cluster. However we have left it as a brooch for you to decide, do message if you would like a quote for converting it.