I have found one of my mothers rings its gold but turns silver colour where 3 stones are set, I think its small dark sapphire with diamond type stones either side. It is stamped as follows
H S 18CT PLAT ? A 332

The ? Is a stamp rectangula shaped with 3 lines across each other similar to a rough scetch of a star

Any help would be greatly appreciated thanks

I too have a ring labelled 18ct [HS] plat L2398. It was purchased as an engagement ring for my grandmother before the first world war. It is a rounded top with hand cutting around the collection of diamonds in the platnum top. The ring is of 18 carat gold. I would love to know where it was made ( England?) and by whom.
Susan