This is a wonderful sterling silver brooch made in a mod “burst” design.  The piece is constructed with a broken up stone in its center that has a polished raised “splash” emanating from it against a blackened background, echoed in shape to the splash.  What I get from the design is that something is exploding and the silver represents the resulting blast waves, but I guess that it could be left to interpretation.  The piece has both a pin and a hook at the back so the that it can be worn either on a chain as a pendant or as a brooch.  The back is stamped “925 Sterling JH Taxco” along with the number 3 within the Eagle assay mark.  I have not been able to identify the maker, but the number 3 Eagle mark was shared by some excellent Taxco silversmiths, including Bernice Goodspeed, Sigi, Hector Aguilar, Marciela and Ledesma, but was also used simply as a generic mark denoting Taxco.  It measures 2” by 1 1/8” and weighs 10 grams.  It is in very good condition with no wear - I have not polished the brooch.

This is a rather unique and interesting design that pre-dates 1979 (when the Eagle system was dropped for a letter and number system).  Vintage, yet modern……