Absolutely stunning 1960s Mexico eagle mark 12 abalone inlay butterfly brooch

Fabulous highly iridescent genuine abalone shell carved and inlaid in solid 925 sterling silver. A real treasure and rare inlay in the body of the butterfly (usually pieces like these have just a silver body). Purples, blues, and greens. Stamped "HECHO EN MEXICO STERLING" with an eagle mark 12. In 1948 the Government of Mexico promoted the reintroduction of the "eagle mark" to identify the manufacturers of silver items. The "eagle" was stamped with a number associated to a silver manufacturing company. This system was unsuccessful, eagle stamps were misused or "loaned" to more than one artist of maker and was abandoned in the 1980s. Roll-over clasp, works well. Deep, dark gorgeous patina. Price is FIRM.