Trying to determine the age of these plastic brooches

I'm having a difficult time determining the age and plastic type of these brooches. They're large - almost 6 in long. The outside "finish" is cracking as well. I've looked through a bunch of old ads and reference books, but I can't find anything similar to this design. I've read that early cellulite can fracture with age, but it doesn't feel like cellulite to me. And it's definitely not Bakelite. Any ideas would be greatly appreciated!