Topaz is a gemstone of the silicate mineralogical family and the subcategory of mesosilicates. More specifically, it is an aluminum nesosilicate that may also contain traces of iron, chromium, magnesium and titanium. Listed as a fine stone, it is a crystal often used in jewelry.
Being able to be of different colors, it is said to be an allochromatic gem. In addition, because of its physical and chemical properties, topaz can have a different color depending on the angle of observation. In general, its best-known color is blue, but this is actually the result of treatment by natural radiation or by the hand of man. Indeed, when heated, topaz can then turn from pale yellow to a darker pinkish hue. The famous blue is obtained by a process of irradiation.