Vintage Genuine Diamond 10k gold and sterling silver R Initial pendant necklace

there are 3 small genuine diamonds on bale as well as a few small diamonds around the R. the R is also surrounded by 10k gold. the pendant is solid not Hollow. I don't know who the maker is but it's an old piece. there are some scratches on thw silver around the R. necklace is a rope chain 16" pendant is around 1"