They appear to be antique pearls using a "925" stamp on a single aspect of clasp & "OW" & a world in packing containers, so three bins made up of Each and every letter & 1 symbol. just like this graphic I designed. https://frasercxiv728183.blogrelation.com/34836343/the-single-best-strategy-to-use-for-gold-south-sea-pearl-necklaces