Antique hard stone cameo brooch

Description:An early 1900's 14k two tone yellow and rose gold framed black & white onyx cameo brooch. The frame is yellow gold with rose gold ornaments. Has a c-clasp with safety lever. The cameo measures 1 1/2" x 1 1/8" and is a Bacchantes maiden facing left with a grape leaf wreath in her hair carved in 2 layers of banded onyx (chalcedony). The back has white swirl marks that is common in chalcedony. It is also my opinion that the cameo is older than the frame due to the Roman nose carved on the maiden. Unmarked but electronically tests 14k. Circa, 1920's.

Measurements: Measures 2" in length by 1 5/8" in width.

Condition: Very good with minor surface crazing on the face and upper torso noticeable upon close inspection. It appears that these lines are part of the onyx layer and not due to damage as there are no chips or actual cracks to the carving.