Essex crystals emerged around the mid-19th century and animals and birds were a favorite subject. Rock crystal was cut en cabochon and on the back, an image was carved in reverse and hand painted. Sometime, like these examples, they were backed with mother of pearl.
They were produced with various levels of artistry, and during the 1920s, copies emerged that were pressed glass to imitate the look. Sometimes you hear them referred to as Cook's crystals, or reverse crystals. By the 1940s their production seems to have waned.
This is a charmer of a bracelet in 14k yellow gold. Four crystals represent various breeds of birds, a cardinal, possibly a red and yellow finch or goldfinch, and a towhee.
Each of the feathered friends rests on a branch with leaves and is backed by mother of pearl to enhance the three dimensional vignette.
Between are oval gold links and at each end a bow motif link that resembles crossed leaves. For the nature lover or avian enthusiast or simply because it is irresistible.