A most wonderful piece showing the Edwardian to early Art Deco style is this Antique Necklace, Vintage Czech Black Onyx Glass and Hematite with marcasite, circa 1910-1920's Era. This necklace has Czech black onyx faceted glass at center and is highlighted by antique marcasite. The chain is adorned with hematite beads. The necklace is about 16 1/2 inches long and is in beautiful estate condition with one missing marcasite. The chain and clasp are sterling silver and the rest of the settings are silver overlay with an aged patina acquired over the years. The pendant portion measures about 2 7/8 inches long by about 1 1/16 inches wide. A wonderful example of original early Art Deco Period.