Antique 18ct Gold & Garnet, Glasgow Hallmark 1870, Single Stone Ring

Very rare Victorian Scottish ring of 18ct gold with a single stone a reddish purple garnet, the type that looks a bit like a ruby, it's not it is a garnet. Assayed and hallmarked in Glasgow in 1870, maker J.W, possibly James Watson of Aberdeen as he had a mark registered in Glasgow and who was active 1847 to 1886 Size is K.1/2 and Us is 5.1/2; band width 3 mm; head width 5mm. There is a tiny tiny chip on one facet of the garnet partially hidden by a claw and difficult to see, I did consider changing the stone but decided not to, as it is all original.