Through much of history, all yellow gemstones were considered topaz and all "topaz" was thought to be yellow. Topaz is available in many colours, and it’s likely not even related to the stones that first donned its name.
The name topaz derives from Topazios, the ancient Greek name for St. John’s Island in the Red Sea. Although the yellow gemstones famously mined there probably weren’t topaz, it soon became the name for most yellowish stones.
Pure topaz is colourless, but it can become tinted by impurities to take on any colour of the rainbow. Precious topaz ranges in colour from brownish orange to yellow and is often mistaken for smoky quartz or citrine quartz, respectively—although quartz and topaz are unrelated minerals.
The most prized colour is Imperial topaz, which features a vibrant orange hue with pink undertones. Blue topaz, although increasingly abundant in the market, very rarely occurs naturally and is often caused by irradiation treatment.
The largest producer of quality topaz gemstones is Brazil. Other sources include Pakistan, India, Sri Lanka, Russia, Australia, Nigeria, Germany, Mexico, and the U.S. — mainly California, Utah, and New Hampshire.
Measuring 8 on the Mohs scale, topaz is a very hard and durable gemstone. Its perfect cleavage can make it prone to chipping or cracking, but when cut correctly, topaz makes very wearable and durable jewellery.