Like diamonds, colored gemstones are graded in quality based on the four Cs: color, clarity, cut, and carat weight. There is also a fifth factor, transparency, that is used to grade colored gemstones. When selecting loose colored gemstones, learning the 4Cs can help you make the right choice in terms of preference and cost.

Many colored gemstones receive heat, irradiation, or other treatments to improve color or clarity. Some of these are accepted industry practice, particularly if the color change is permanent. Also on the market are various synthetic colored gemstones which are getting harder to tell apart from natural gemstones.

To better inform you, we also talk about imitation colored gemstones as well as common gemstone misrepresentations and false claims.