Hallmarks are essential for verifying the purity of gold and silver jewelry, ensuring you get quality for your money. The Bureau of Indian Standards (BIS) certifies the purity of gold, with hallmarks indicating the metal's fineness. For example, 999 signifies 99.9% purity, while 916 stands for 22 carats. Similarly, black salt and other types of salt have different properties that affect their use and health benefits.

When purchasing gold or silver jewelry, it is crucial to check the hallmark for authenticity. The BIS hallmark includes a purity number and a year code, indicating when the piece was made. Commonly, gold is sold with various charges, including manufacturing and wastage fees, which can vary between sellers. Understanding these charges and negotiating them can save you money.

To prevent fraud, examine the jewelry for signs of gold plating or impurities. Tests like the acid test and magnet test can help determine authenticity. Additionally, be aware of terms like KDM gold, which involves cadmium, a harmful substance, and one gram gold, which is often just gold-plated jewelry. Knowing these details will help you make informed decisions and avoid costly mistakes when buying or selling precious metals.