Help identifying clamshell pendant

[Kelgen]

Hi there! Any information about the maker would be so helpful!

This belonged to my gg - grandmother, I think. She lived from 1916-1991, if that helps. The chain’s clasp says “STERLING”. The pendant’s bail has “925” in a semi jagged cartouche? The pendant itself has the letter “D” and next to it, very faintly, “925”.

Thanks in advance!

[JeffTucker]

The “925” refers to the purity of silver - 92.5% That’s the standard for sterling silver, so that’s spot on. The “D” could refer to almost anything. Outside of the U.K., silversmiths largely used whatever hallmarking system struck their fancy. So, it could be a date letter, or the maker’s initial.