What a stunning set of Jewellery. Do the stones feel cold? If yes this indicates natural stones. The sharp facet lines, no scratches or surfaces grazes visible peripherally, could and I do mean "could" indicate natural gemstones. i.e citrine or yellow topaz. Do you know if the metal is Silver? Also it is very hard to see the shape of the S to cross reference. Any chance of another photo of the mark? A very beautiful old set and in great condition too. The colour of the stones against the aged appearance of the metal enhanced by the inclusions of marquisites is a showstopper.
