The easiest way to tell if gold is real is to look for a stamp, which will typically be on the inside of a piece of jewelry. The stamp should indicate the purity of the gold in karats, and will usually be an abbreviation such as 10K, 14K, 18K, or 24K. Additionally, a magnifying glass or loupe may be used to inspect the color of the gold. Real gold will generally have a slightly yellow hue, while fake gold may have a more greenish or silvery tint.