Description | Topaz, Al2SiO4(F,OH)3 (aluminum silicate fluoride hydroxide), is a common gemstone that has been used for centuries in jewelry. Its golden brown to yellow color is classic but is confused with the less valuable citrine, which is sold under the name topaz. The blue topaz that is often confused with aquamarine is rarely natural and is produced by irradiating and then heating clear crystals. |