The pendant type is lavalier.
The silver hallmark eludes me but that is a very nice set of jewelry. At first I thought the mark was a bird, but now I see the "LS", which could mean "Louis Stern" but the pieces look nothing like what I find of theirs online.
Is that a bracelet or ring at top? Can't get my head around the scale of the pictures.
I think it's a bird. It is nice work, but I can't find anything on it. Sometimes I've solved unidentified makers by just scanning [signed sterling/.925] under jewelry on eBay and stopping to look closer on everything that looks similar in style and design. Who ever made them were pretty skilled and should be a notable silversmith I'm thinking?