|Gemstones and Other Materials
|1.65ct I VS2 Old mine cushion cut diamond - with GIA certificate
2 x pear shape diamonds - total weight 0.36ct
|18ct yellow gold and platinum with maker's marks and London assay marks
|UK finger size L, US finger size 5.75 (can be adjusted to any size)
Front centre: 6.9mm
Old mine brilliant cut diamonds are sometimes referred to as old miners or OMBs and are either square or rectangular diamonds with obviously rounded corners and sides. This softened profile is called a cushion shape as the convex edges and curved corners are said to resemble an actual cushion.
The style developed during the 18th century after the discovery of diamonds in Brazil in about 1725. This facilitated experiments in cutting due to the large increase in available stones. Eager as ever to retain as much weight as possible, cutters still followed the overall shape of the rough crystals but now corners became more rounded and the number of facets was increased. The profile proportions of the stones also echoed the rough with the crowns being relatively high and the top table facet generally fairly small. Another typical feature of these stones is the point at the bottom of the stone, known as the culet, which was usually polished flat.
The discovery of diamonds in South Africa during the late 1860’s coincided with revolutionised mechanical cutting methods. This saw the fashion for new circular cut diamonds begin to replace these cushion shaped stones which then became known as ‘old mine’ diamonds. Today the name ‘old mine brilliant’ still describes a cushion shaped diamond with a small table facet, high crown and polished culet. These features enable old mine cuts to display a huge amount of fire (the coloured flashes of light you see in a diamond) and life.