How to Tell Genuine Gold

Examine the piece using a jeweler's loupe for a stamped or laser-etched hallmark. On chains these are usually placed near the clasp, while it will be somewhere in the interior of trinket boxes, cigarette cases and watches. You're looking for one of three possible three-digit numbers: "375," "585," "750" or a figure in carats, such as "9 ct," "14 ct," "18 ct." The presence of these marks is a certain indicator of genuine gold.

Use a testing kit. Available online from online accessories stores, the kit consists of a series of vials of acid prepared in different concentrations to test for gold of various purities. You apply a drop of acid and if there is no reaction, the item is genuine gold.

Weigh the item in the palm of your hand, comparing the weight to that of an item of similar size you know to be base metal. An item made of solid gold is discernibly heavier than a base metal item. Although this is only a rough and ready unscientific test, it is useful in situations such as yard sales.

Scratch the item with the end of a pin. Gold is extremely soft, so the point should sink in like a knife into butter. If it jars against the metal, then this is a strong indicator that the item isn't genuine gold. Once again, this isn't a definitive test, but it is a useful guide.