Taxco Modernist Sterling retailer Mosaic Pin Pendant

Awesome vintage Taxco Mexican sterling pin-pendant in a modernist design. Unusual raised silver shape with a mosaic of several different colored stones in the center. The outside of the silver design steps down and is shadowed in black for a nice feeling of depth. On back is a pinstem and loop at top for hanging on your chain. It's marked "925 retailer Sterling Taxco", and has indecipherable maker's initials inside the sterling mark. Also there's the number 3 eagle assay stamp. some other things I'm unsure of.

Brooch-pendant measures 1 1/8" x 1 7/8" and is in beautiful vintage condition with no issues.