Green buying Turquoise Mexican Sterling Brooch

This brooch buying is clearly marked "Mexico Sterling" on the back. It has small round green turquoise cabochons in settings and the brooch itself is in the shape of a lyre, or harp. It is about 2-1/4" tall and 1-1/2" across. It looks like it has been cleaned and must have had a dark patina at one time. The very sharp pin has a basic closure. The brooch shows wear and age but is undamaged. It will ship insured via First Class Mail