Hallmark: The easiest method is to look for a hallmark—a stamp on the gold item (e.g., 916 for 22k or 750 for 18k). This certifies its purity, though it’s wise to be cautious of fake stamps.

Acid Test: A common jeweler’s method, this involves scratching the gold on a special stone and applying nitric acid. This is quick but can slightly damage the item.

Electronic Testers: These non-destructive devices use electrical conductivity to give a quick reading of the gold’s purity.

XRF Spectrometry: The modern, non-destructive standard used by professionals. An XRF machine analyzes the item’s elemental composition using X-rays, providing a precise and instant breakdown of the metal.

Fire Assay: A small sample of gold is melted to separate it from other metals, leaving a pure gold button that is then weighed to determine the original purity