COLOR TYPES FOR TOPAZ
Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F, OH)2. Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and other faces. It is one of the hardest naturally occurring minerals (Mohs hardness of 8) and is the hardest of any silicate mineral.
Most topaz is colorless, yellowish and brownish colors are common. Colorless topaz can be heated, irradiated, and coated with thin layers of metallic oxides to alter its color.
Topaz stones, known as "mystic topaz," appear to change color if the observer moves the stone under a light or changes the angle of observation. These coatings are also thin and can be worn through during wear.
“Sky blue”, "Swiss blue" and "London blue" are trade names for three of the most common varieties of treated blue topaz.
Topaz should be cleaned carefully with warm soap and water. Steam and ultrasonic cleaning should not be used.
One of the most important benefits of wearing gemstones is that they always help to drive away negative forces.
Imperial topaz is yellow, pink (rare, if natural) or pink-orange. Imperial topaz can often have a bright yellow to deep golden brown hue, sometimes even violet. Many brown or pale topazes are treated to make them bright yellow, gold, pink or violet colored.
Mystic topaz is colorless topaz which has been artificially coated via a vapor deposition process giving it a rainbow effect on its surface.