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

Era: Edwardian 1901-1910
Metal: 15 carat gold and platinum
Gemstones: old cut diamond 4.98x4.68mm, rose cut diamonds x12, opals x12
Weight: 4.1g
Size: 17.8mm diameter 
Drop: 25.8mm inc. bail
 
A delightful pendant, 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 open 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 very slight hint of warmth to the colour. It is eye clean and bright.
 
We made this into a pendant, from a bar brooch, using the metal from the bar, so the bale of the pendant is 15ct gold and topped with platinum, just as the bar was.