As with all light colored gems, the value of the topaz increases with its intensity of color. Topaz has a definite sky-blue color and is uniform in color, often without overtones. While it is often pale, it can also be bright or sometimes even an intense blue. It can sometimes also have a slight gray or even greenish tinge.
Topaz is an aluminum silicate that contains up to 20% fluorine or water. Its physical and optical properties vary according to the proportions of water and fluorine present. Golden brown and pink topaz contain more water and tend to form longer crystals. topaz is one of the hardest silicate minerals. It makes an excellent mineral specimen because of its high luster, attractive colors and well-formed crystals.
Topaz produces some of the largest crystals. They can be up to 3 feet long and weigh up to several hundred pounds. The largest stones have been nearly 20,000 carats. One of largest topaz stones in the world sits in the Museum of Natural History in New York City. It comes from Brazil and weighs a shocking 600 lbs! The largest cut topaz, the pale blue “Brazilian Princess” found at Teofilo Otoni North of Rio de Janeiro, weighs 21,327 carats and was fashioned as a square cut. It is now on display at the Smithsonian Institution in Washington DC.
Caring for your Topaz Jewelry
The best way to clean topaz is with warm soapy water. Never clean topaz in a home ultrasonic cleaner or a steamer. It is important that the stone be protected from any sort of exposure to rapid temperature change, acids, or heat. A topaz stone will start to lose its color if kept out in the sun or exposed to other kinds of heat. topaz is relatively hard but can crack easily if dropped so handle your topaz with care.