This is an identified 1960s DeLizza & Elster Juliana topaz rhinestone brooch. It's a combination of oval and navette topaz glass stones and green, gold & orange round rhinestones. Plus a touch of aurora borealis coated golden stones. They are all prong set on gold-tone metal in two layers.
DeLizza & Elster designed and manufactured their jewelry from 1947 to 1990. Their well known bold design with colorful specialty stones collection was called Juliana. Later collectors refer to all D&E's jewelry as "Juliana." They never signed/stamped on their jewelry but used a paper tag. I love this kind of challenge to verify them by knowledge of construction.
Dimensions: 2.25 x 2.13 x 0.75 inch