A white gold single stone cushion cut diamond ring

A white gold single stone cushion cut diamond ring,
with diamond set shoulders, with a cushion set diamond, estimated as approximately 0.90ct, milligrain set in a plain pierced collet, with an old eight cut diamond, grain set at either side to a triangular collet, open shoulders to a later half shank. Marked 18ct. Head 12 x 7.10mm, 3.13g. Diamond assessed as approximately:
Colour: L/M
Clarity: VS1/VS2.
Finger size Q
Sold for £1,000

Condition report:
It is possible the diamond may ultimately weight in excess of 0.90ct as the setting edge is substantial.