As the emperor's adopted sons and joint-heirs to the Roman Empire, Lucius and Gaius had promising political and military careers. However, Lucius died of a sudden illness on 20 August AD 2, in Massilia, Gaul, while traveling to meet the Roman army in Hispania. His brother Gaius also died at a relatively young age on 21 February, AD 4.
Reverse: Lucius Caesar and Caius Caesar facing, wearing toga, holding shield on the ground and spear, simpulum and lituus (b9) above; AVGVSTI F COS DESIG PRINC IVVENT / C L CAESARES
Die Orientation: -
Weight: 3.61 g
Reverse: C L CAESARES AVGVSTI F COS DESIG PRINC IVVENT, Gaius and Lucius Caesar standing, each, wearing togas, resting hand on shield and spear, simpulum, right, and lituus, left, flanking, left and right respectively
Die Orientation: 4 H
Weight: 3.8 g
Reverse: ΛΕVΚΙΩΝ, Bare head of Lucius facing right
Die Orientation: 12 H
Weight: 3.79 g
RPC specifically calls the metal brass.