Reverse Along the upper edge of the coin, a Latin inscription reads 'PORTUGALIAE ET ALGARBIORUM REGINA', translating to 'Queen of Portugal and the Algarves'. The beginning and end of the inscription are separated at the top by a relief flower with eight petals. In the central part, a wreath formed by two olive branches tied at the base with a bow. Inside the wreath, the Roman numeral 10 'X' separates the mint year '17 79'. Below is a relief four-leaf clover.
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, the coat of arms of Portugal crowned with an imperial crown: on the heraldic shield, five small Portuguese shields arranged in a cross, each with bezants; around the large shield is a wide, indented border with seven castles. The heraldic shield is framed by relief elements in the Rococo style.