Watch List notes:

ROMAN AND BYZANTINE COINS

Caesarea, Cappadocia. Trajan, 98-117. As (Orichalcum, 22mm, 8.35g 6), Rome, February 116 - early August 117. IMP CAES NER TRAIANO OPTIMO AVG GERM Radiate and draped bust of Trajan to right. Rev. DAC PARTHICO P M TR POT XX COS VI P P S C within laurel wreath. BN 953ff. Cohen 122. RIC 644. An attractive and well struck example with a fine olive-brown patina. Extremely fine.

From a Swiss collection.
This coin forms part of those exceptional issues produced in Rome for use in a specific province or region of the Empire, in this case, Asia. It is clearly set apart from normal Roman Latin issues by its unusual size (it is smaller than an As but larger than a Semis), its unexpected metal (orichalcum) and the emperor's radiate head dress (appropriate for dupondii but not for anything smaller).