Taxco Sterling Silver Vintage Butterfly Brooch Pin

Butterfly brooch with inlaid abalone shell and sterling silver setting. I'm not sure if it was produced this way, or something a previous owner did, but there is a light type of coating on the abalone shell that gives it an absolutely incredible frosted matte look with hints of flash and color. 

• Size: 1 1/2" x 1 5/8" in size.
• Type: Pre Owned Mid Century Vintage from the 1960's. 
• Condition: Darkened patina on the sterling. Pin back in good working condition.
• Materials: Sterling silver, abalone shell.
• Markings: Marked on the back with eagle mark 3, Taxco 925 Hecho en Mexico, and an artist's mark that looks to be SJB on the inside.
• Weight: 5.2 grams.