Topaz buyer’s guide

Color names

Colorless, yellow, pink, and sherry stones occur naturally. “Imperial” is a trade description for a strong orange-pink to reddish orange. It is not a species. Blue topaz in the general market is often irradiated and then heated to produce the blue. A listing should say if the color is the result of treatment when that is known.

Do not confuse topaz with citrine, heated amethyst sold as a yellow stone, or sapphire. Refractive index separates them. A photo of the color does not.

Wear

A bezel or a setting that covers the girdle is kinder than a high prong that leaves an edge exposed to knocks. Ultrasonic cleaners and steam are a poor idea for a cleaved stone. Warm water, a soft brush, and a mild soap are enough.

Large topaz can look like more stone than the carat suggests because the density is lower than sapphire. Check the millimetres. A 10 millimetre stone and a 10 carat stone are not the same sentence.

On our listings

We state color, measurements, and treatment when we have them. If the title says unheated, read that as a statement about the item, and ask if you need the basis for it. The carat calculator’s topaz default is a check on weight versus size, not a valuation.