F

faceted cultured pearls

pearls carved to create rhombic or triangular surface shapes and yield a sparkling optical effect when the wearer moves.

first-generation cultured pearls

 freshwater or saltwater cultured pearls whose growth is started by implanting a tissue piece, or a bead nucleus and tissue piece, in a host mollusk that has not grown a pearl before

flame structure

produced by aragonite crystals organized in two directions that are often intertwined

freshwater pearls

 pearls grown in mussels in a non-saline environment