Vintage 1980’s Multicolored Acrylic Jeweled Black Brooch

Item is in good used vintage condition Light to medium wear May need a cleaning if desired No makers marks Costume Brooch Weight is 18.6 grams Appears to me to have been made in the 1980’s… Could have been handmade… not sure.. I had a pair of earrings similar to this in the 80’s…that was the style back then… Pin back (mechanism) is in working order Appears to me to be some type of black metal and acrylic? Rhinestones…there not cold to the touch like glass or stones would be… Note: on the back of the brooch the silver-tone pin that attaches to the brooch is not perfectly straight