Topaz Topaz Pictures
 Topaz comes in many colors such as blue, yellow, pink, brown, green and clear. Sherry Amber or Orange-red "Imperial Topaz" is rare. As with all gems, protect topaz from scratches and sharp blows. Also avoid large temperature changes (such as leaving it be a heater vent or in a hot car). Do not clean topaz in a home ultrasonic cleaner. The best way to clean topaz is warm soapy water. Clear topaz is commonly irradiated and heat treated to become other colors such as blue. Yellow and brown topaz is often heat treated to become pink topaz. Natural pink or blue topaz is very rare.

Reputable dealers will not use the following misleading terms. "Bohemian Topaz", "Madeira Topaz" and "Occidental topaz" are really yellow quartz (also known as citrine). "Nevada Topaz" is really smoky obsidian. "Spanish Topaz" is really orange-brown quartz.

The Topaz found in the Utah desert is Imperial Topaz (or of a "sherry amber" color) when found inside the rock (generally a silvery rhyolite), and bleaches out to a clear color when exposed to sunlight for around 2 to 3 weeks. There is also some Imperial Topaz found close to the Thomas Mountain Range that bleaches to a pale pink color. This type of Topaz is extremely rare and highly prized.

Topaz is found in Africa, Australia, Brazil, China, Japan, Mexico, Myanmar, Nigeria, Pakistan, Sri Lanka, Russia, and USA (Colorado, Maine and Utah). Topaz is found in Beaver, Juab and Tooele counties of Utah.

Chemistry: Al 2 SiO 4 (F, OH) 3, Aluminum silicate fluoride hydroxide.
Class: Silicates (the hardest of the Silicate gems)
Subclass: Nesosilicates
Uses: gemstones and optical properties are useful in industry.
Specimens: Topaz is a common gemstone that has been used for centuries in jewelry. Its golden brown to yellow color is classic but is confused with the less valuable citrine, which is sold under the name topaz. The blue topaz that is often confused with aquamarine is rarely natural and is produced by irradiating and then heating clear crystals.

The structure of Topaz is controlled by a chain like structure of connected irregular octahedrons. These octahedrons have an aluminum in the middle surrounded by four oxygens. Above and below the aluminum are the hydroxide or fluoride ions. The chains of octahedrons are held together by individual silicate tetrahedrons but it is the octahedron chains that give topaz its crystalline shape. Topaz is the hardest silicate mineral and one of the hardest minerals in nature. However it has a perfect cleavage which is perpendicular to the chains and is caused by planes that break the weaker Al-O, Al-OH and Al-F bonds. None of the stronger Si-O bonds cross these planes. Topaz crystals can reach incredible size of several hundred pounds. Topaz can make very attractive mineral specimens due to their high luster, nice colors and well formed and multifaceted crystals.

PHYSICAL CHARACTERISTICS: