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 91'. 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', on the left 'DEI . GRATIA', translating to 'Maria I by the Grace of God'. The inscriptions are separated at the bottom by a four-leaf clover. In the central part, the coat of arms of Portugal crowned with the imperial crown: on the heraldic shield, five escutcheons with bezants are arranged in the form of a cross; around the large shield is a wide, fluted bordure with seven castles. The heraldic shield is framed by relief elements in the Rococo style.