Gold jewellery often features purity marks that indicate the percentage of pure gold it contains. In India, the number 916 signifies 22-karat gold, which contains 91.6% pure gold, while 750 represents 18-karat gold with 75% purity. The 585 mark indicates 14-karat gold, containing 58.5% pure gold, commonly used for lighter and contemporary pieces. The highest purity mark, 999, denotes 24-karat gold, which is 99.9% pure but too soft for most jewellery designs. In India, jewellery is certified under the hallmarking system regulated by the Bureau of Indian Standards (BIS), ensuring that purity has been independently verified. Hallmarked jewellery carries the BIS logo, the purity mark, and a unique identification code, helping buyers trace and verify their purchases. While higher purity generally means higher value, the final cost also includes making charges, wastage, and taxes.