This is a rare and beautiful antique Frost Workshops Arts and Crafts era brooch made of brass with a verdigris surface and a pinkish-purple cabochon centerpiece. Frost Workshops operated in Dayton, Ohio, from approx. 1906-1913 and pieces like this are quite scarce.
The brooch measures approx. 1 7/8 inches long and 3/8 inch wide and has a period C clasp. It is in good antique condition with light age-related wear/patina/verdigris to the surface. I have not cleaned it.
It is signed with Frost's triangle maker's mark, which is only partially visible due to the heavy verdigris/patina/sediment on the back of the brooch (see last photo).
A very special Arts and Crafts period collector's piece!
(The box in photos is for display purposes only.)