At one time, nearly all yellow, brown and sometimes green gemstones were called topaz, which can lead to some confusion even today. The term "smoky topaz" was once commonly used for smokey quartz , and citrine was once known as "golden topaz". These misleading trade names are no longer acceptable in the gemstone market, but are still found from time to time. True topaz is sometimes called precious topaz to avoid any confusion with other stones. Blue topaz is a widely available and affordable form of treated colorless topaz.