Topaz is the birthstone for September, the gem for the zodiac sign Scorpio.
Topaz is a fairly common and inexpensive gemstone.
Pure topaz is colourless and transparent but is usually tinted by impurities. Naturally occurring topaz is a often golden brown to yellow, and is sometimes confused with the less valuable gemstone citrine. Other colours such as wine red, pale gray, reddish-orange, pale green, or pink (rare) occur.
Blue Topaz does occur in nature, but is rare and almost always lightly coloured. Most if not all blue Topaz used in jewelry has been irradiated and heat treated to artificially create the blue colour. The original stones are colourless, gray or pale yellow or blue material, and the radiation process gives them their deep sky-blue colours.
Imperial topaz is yellow, pink (rare, if natural) or pink-orange. The pink and red varieties come from chromium replacing aluminium in its crystalline structure. Brazilian imperial topaz can often have a bright yellow to deep golden brown hue, sometimes even violet. Many brown or pale topaz are treated to make them bright yellow, gold, pink or violet coloured. Some imperial topaz stones can fade on exposure to sunlight for an extended period of time.
Mystic topaz is colourless topaz which has been artificially coated via a vapour deposition process giving it a rainbow effect on its surface.
Topaz is also a plechroic gemstone and can have varied colour intensity when viewed at different angles.
Topaz can be opaque to translucent to transparent depending on the impurities. It can form in very large sizes and tends to be naturally free of inclusions.
Topaz is a hard (8 on the Moh’s scale) and durable gemstone, and will not dissolve in most chemical solvents. However, it does have perfect cleavage which can make it prone to chipping or forming flaws if it receives a sharp impact along a particular plane.
Care should be taken when wearing or storing them around other gems and jewelry as topaz can scratch softer gemstones. If possible, wrap them individually in a soft cloth or place them separately inside a fabric-lined jewelry box to prevent stones from rubbing against each other. Use only a mild soap or detergent and warm to room-temperature water to wipe down your stones with a soft cloth or brush.