When my virtual friend Irina Belinskaya sent me a gift that she made for me (you can read here about it), she also included this enameled piece. This is something very Russian that people buy when they go there as tourists. Russian people themselves also like it and wear filigree jewelry with enamel a lot.
When I unpackaged my gift, some packaging paper fell out and was picked up by my dog. I am glad Irina mentioned that there was something for me for jewelry making! I started searching and found this: