Blue Lapis Glass (?) necklace Anyone know the period and Maker

I bought the necklace 35 years ago at an estate sale. I've seen other Deco lapis glass necklaces but they don't look like this one. These beads are strung on a chain and the writing on the clasp looks almost like it was scratched into the bead. The metal beads are half round solid on one side and the other side has four cut sections that were bent to form a bead. When I first acquired the necklace I thought I found 1900 stamped into it somewhere but now I can't find it. Because I haven't found another that looks like this one I was wondering if you can help me to know the date and maker of this necklace- Thank you so much! Nancy