Reverse Along the upper edge of the coin is a Latin inscription 'PORTUGALIAE ET ALGARBIORUM REGES', translating to 'Kings of Portugal and the Algarve'. The beginning and end of the inscription are separated at the top by a relief flower with eight petals. In the central part is a wreath formed by two branches tied at the base with a bow. Within the wreath, a quatrefoil is positioned at the top, below it the Roman numeral 3 'III', beneath that the year of minting '1777', and above the wreath's bow, a second quatrefoil.
Obverse Around the edge of the coin are decorative raised denticles. Along the rim are Latin inscriptions: on the right 'MARIA I ET PETRUS', on the left 'III DEI GRATIA', translating to 'Maria I and Peter III by the Grace of God'. In the central part is the lesser coat of arms of Portugal crowned with an imperial crown: on the heraldic shield are five escutcheons arranged in the form of a cross, each with bezants, and around the large shield is a wide, fluted bordure with seven castles. The heraldic shield is framed by relief elements in the Rococo style.