Lovely pair of screw-back earrings stamped with "Sterling Taxco", the initials "ROA", and the Mexican Eagle #3 mark which dates them between 1955-1980.  The tops of these earrings have a floral pattern that is inlay with abalone shell and embellished with lapis that is set inside a framework of silver filigree.  The screw-back findings are labeled "alpaca" which is different from the sterling tops.  Alpaca is a metal with a high nickle content which is sometimes used for jewelry findings.  They measure 1" in diameter.  SORRY. THIS ITEM HAS ALREADY BEEN SOLD!

View of mark: