This is a vintage multi rhinestone cluster starburst or sunburst brooch or pin pendant combo with round rhinestones with a pin bar and pendant ring on the back made in the USA in the 1950s.

The 18 inch long gold plated cable chain is more recent.

The unmarked brooch or pin measures pendant pin 1.5 inches in diameter; chain 18 inches long and is in excellent used vintage condition.

It's just beautiful.