Very Early White Plastic Flower Brooch with Goldtone Accents and Clear Rhinestones

I think this is a very early celluloid plastic but I am not familiar with the plastic well enough to be sure. It is molded in pieces with the total base in one piece. Gold stamens have been added with an extra white flower on the middle flower and clear rhinestones in the middle of each. I believe these stones are also plastic. It is 3 1/4x1 5/8" and has the old time c-clasp poured right into the plastic. I believe it is from the 20s or 30s.