Large Unmarked Aurora Borealis Vintage Brooch

This large and heavy unmarked beauty looks so much better in reality than on these pictures (It doesn’t look blue but rather golden). I posed the similar ones earlier but I wanted to show them as a group. Based on the backs, I believe that all of these three AB brooches were made by different manufacturers.

I am guessing that all of these brooches might have been made in the 1960's or early 1970's.

Thanks for looking:)