The clasp is gorgeous. I would like to see more photos of the whole piece, too. If you click on Post Reply at the bottom of this message you will be taken to the top and can insert the
image(s). It took me awhile to figure out how to do this.
I think the stones are marcasites. The clasp looks Deco; the molded glass certainly resembles Lalique, and may be French. There are so many unmarked pieces of jewelry from this period but I haven't seen many with molded glass like this one. KK is correct that you can usually identify Czech jewelry from the style, and the components. However, most stones used in pre-WWII jewelry made in the US were imported from Bohemia, (what is now the Czech Republiv and Slovkia) and Austria - as were many of the findings used in jewelry manufactured in the US. Providence, R.I. was the costume jewelry capital of the world.
Some Czech costume jewelry is marked - not just pieces set in gold and silver. Czechoslovakia was formed right after WWI so anything marked that way cannot be earlier than 1918. It was dissolved at the beginning of WWII, reformed after WWII, and then split again in 1992. The country has a long turbulant history best read on wikipedia. Some pieces are marked with different spellings, sometimes depending on where they were being exported to. I remember Ginger Moro explaining the French spelling of the country on Jewelcollect. I do not think the purse or the clasp are Czech or German.
Hope this is not adding to the confusion.
Linn