A versatile species of gemstones, Topazes are available in a variety of colours and colourless forms. Often identified by the hue name, such as pink or blue topaz, some of the most expensive and rare topaz have commercial names given to them. The high values red and pink stones are known as Imperial Topaz while the terms Precious Topaz or Sherry Topaz refer to stones with a rich yellow to a medium, peachy orange colour.