RGP = Rolled Gold Plate. This is where a layer of say 14 kt solid gold is fused to a base metal, usually copper or brass.
Like today's electroplating a very, very thin layer. A marking must state the actual percentage of karat gold, such as 1/30 14K Gold Overlay, which is possibly the 1-30 mark on your ring.
My guess is that the stone is crystal. Diamond would not have scratches on the table. A diamond can only be scratched by a diamond itself. Only a jeweler could tell you that for sure.
Re: Engagement Ring
RGP = Rolled Gold Plate. This is where a layer of say 14 kt solid gold is fused to a base metal, usually copper or brass.
Like today's electroplating a very, very thin layer. A marking must state the actual percentage of karat gold, such as 1/30 14K Gold Overlay, which is possibly the 1-30 mark on your ring.
My guess is that the stone is crystal. Diamond would not have scratches on the table. A diamond can only be scratched by a diamond itself. Only a jeweler could tell you that for sure.
Re: Engagement Ring
Good call ! Anything with a stone need to be examined by a gemologist to determine what it really is, otherwise it's just wistful thinking ;~)
Lovejoy