V2542, Annam Minh-Mang Thong-Bao Coin, (Ming-Ming Tong-Bao), Zinc, AD 1820.
Zinc, VF condition, please refer the picture.
The name of the coin is "Minh-Mang Thong-Bao" in Vietnamese, or "Ming-Ming Tong-Bao" in Chinese language.
Annam Nguyen Dynasty, Minted by first Emperor Nguyen The To during AD 1820 to 1840.
The catalogue No 101.22 (Dr. R. Allan Barker's "The Historical Cash Coins of Viet Nam").
Diameter: 22 to 24 mm.
Weight: around 2.5 gram.