The factors contributing to the presence of defects in metallic antiquities may be due to the nature of metal constituents, method of manufacture, environmental conditions, etc. The variety of defects generally found in metallic antiquities are segregation, porosity, blowholes, impurities, inclusions, cracks, scale formation, corrosion, etc. These defects are frequently encountered in metallic antiquities such as coins of copper, bronze, silver, and lead, bronze, silver, copper, and iron objects collected from various parts of Tamil Nadu. They are discussed mainly in the context of metallographic technique.