Belle Epoque "Naiad & Sturgeons" Brooch, France, c. 1895. Gold, Carved Agate & Pearl. H 3.80 cm (1.50 in); W 3.50 cm (1.38 in) © Tadema Gallery.

A rare depiction in jewelry of a naiad* (fresh water mermaid) encircled by two sturgeon & water lily leaves. It appears that the naiad has called the sturgeon up stream to spawn.
Inspiration & workmanship worthy of a Faberge Jewel. 
A Fin de Siecle homage to caviar? 
*see painting by J W Waterhouse 1896 Hylas is abducted by the Naiads.