Museum hand carved Sardonyx shell early Victorian Bacchante. Pinchbeck(?)/Gold Plated brooch 1835-1865

Circa 1835-1865 hand carved Museum Sardonyx shell -Early Victorian image of Bacchante -priestess of Bacchus - god of Wine and Enjoyment, embedded in the unmarked Pinchbeck or Gold plated hand etched brooch. The total measures is 45 by 39(mm.); weight -8.55 grams. Reasonable Antique condition (a few stress lines and one little boll is lost), cleaned by the jeweler..