Wish I knew. Both my grandmothers had a ton. If it didn’t have real gems we just donated it.I see the same thing at antique malls and shows. Things of high quality I’ve seen years ago are nowhere to be seen today. Highly desirable items are locked up in collections. I am seeking it today in high end costume jewelry. Much of it is being purchased and going to the Asian Rim as investment. In ten years their will be no more costume left in this country