Vintage Art Deco Brooch good - Silver and Green Rectangle 1.5" x .75" - Classic Deco Design - Gift For Her

This classic Art Deco brooch is simple and elegant. The center piece is a beautiful Deco green rectangle of glass or some translucent stone. The encasing metal is silver.
There are two hallmarks on the back. One made up of a circle and triangle and the numbers 80.
I purchased this from an antique shop in Warsaw, and I believe it to have been made in Eastern Europe, but its origin is unknown. good