A cicada has two life cycles. The first is spent in the ground as a larva after which it becomes a pupa. The second phase begins when the pupa splits open and the cicada emerges, as we know it from the ground. Observations of this gave birth to the belief that the cicada was reborn and rose from the dead. During the earliest dynasties it was the custom to place a cicada made of jade with the deceased to bring them immortality.
As an emblem of immortality and resurrection the cicada often appeared on birthday gifts in China, representing wishes for the recipient's longevity.
Jade has always been highly valued in China, in this life and for use in the afterlife. It was thought to have special powers, possibly protective ones however sometimes glass was used as a less expensive substitute. Since the ancient Chinese believed that, after death, jade preserved the corpse jade objects were placed in their tombs as early as the Neolithic period (about 4000 BC).
During the Western Zhou dynasty (1050-771 BC) the practice to cover specific parts before burial of the body with Jade was first used. In the Han dynasty (206 BC-AD 220) this tradition was further developed to that the corpse's nine orifices should be plugged with jade. In this tradition Cicadas made of jade were placed on the corpse's tongue while plaques covered the eyes and plugs filled the nose and ears.