Vintage brooch. At work in the quarry hammering gemstones

This collection came to me as part of an estate.  I can't attest to the material, but believe it is base metal, gold plate and gemstones.  This appears to be a man at work in a quarry, hammering away at a boulder, which is a gemstone.  Approx 1.5" high by 1.1" wide.  Whatever it is, you certainly won't see anyone else wearing anything like it!