Based on Early Italian Renaissance Artwork. 

Strand is made up of Onyx, Gold-plated beads, and Antique Pearls.  The drop consists of an Onyx cabochon in a brass setting on an Antiqued Gold-plated Brass plaque, finished with 3 drops of Onyx beads, and an Antique Pearl.

Toggle Clasp.  Strand is 19", and the drop is 1 3/4".