An ouroboros is an ancient symbol of a snake biting its own tail. Golden necklaces and bracelets, with scale-like or Brazilian chains, of this type were popular during the 1840s. The eyes were usually set with rubies and sometimes the body was decorated with round turquoise cabochons. More expensive models had heads decorated with royal blue enamel, one of the favorite colors during the late 1830s and early 1840s, and diamonds.