Topaz is the original modern birthstone for the month of November. Its position as a birthstone contributes to the gem's popularity. Topaz jewellery can be found for sale in almost every jewellery store. Topaz occurs in a wide range of natural colours; however, most natural topaz is colourless. The most highly regarded colours are the reds and pinks, which receive their colour from trace amounts of chromium. Topaz aids digestion and combats eating disorders, such as anorexia and bulimia. It fortifies the nerves and stimulates the metabolism.