Gemstones 101 - The Topaz
By Kevin Chang
Topaz is a one of the most popular gemstones in the world today along with the ruby, diamond and sapphire. It is available in a wide variety of colors but the golden orange-yellow topaz which is also known as the Imperial Topaz is the most expensive color of all.
Pure topaz is transparent but is usually blemished with some impurities. A common topaz mineral color is yellow. They can also be gray, white, blue, green and other colors depending on the impurity.
The use of topaz as a gemstone goes back to last 2000 years ago. One of the gemstones that form the foundations of the twelve gates to the City of Jerusalem is the topaz. The use topaz in some old civilizations symbolizes beauty and splendor.
The sky blue topaz is a widespread color in today's market and people have always associated topaz with this color. But the fact is it was only until this century that the blue topaz became very popular because this color is inexpensive so many people can afford to buy them. Although blue topaz occurs in nature, most of the blue topaz in the market today are treated with irradiation and heated to turn blue. The most common blue topaz varieties are the Swiss Blue, London Blue and Sky Blue.
The common varieties of topaz gemstone in the market today are the Blue Topaz, Brown Topaz, Green Topaz and Pink Topaz. Naturally pink topaz is very rare and most pink topaz commercially sold has been heat treated from yellow or brownish
stone.
A new trend in using topaz for jewelry is using iridescent colors. The process is done by applying a thin layer of titanium oxide on the stone through physical vapor deposition. The final effect is them marketed as "Mystic Topaz".
Other names for certain types of topaz are Precious Topaz, Imperial Topaz, Sherry Topaz, Silver Topaz, Swiss Blue Topaz, London Blue Topaz and Paraiba Topaz.
One of the most notable properties of the topaz is the cleavage. The structural nature of the topaz has one plane that makes bond relatively weak. The topaz should be handled with extreme care to avoid developing of cleavage flaws.
Commercial topaz deposits can be found in Ouero Prito, Minas Gerais, and Brazil. Gem topaz also comes from the Ural Mountains of Russia and Siberia but the excellent types of topaz mainly come from San Luis Potosi, Mexico. In the United States, topaz gem materials are most coming from Pikes Peak area in Colorado, San Diego California and New Hampshire.
Like many precious stones, topaz should be prevented from scratches and sharp blows. Placing the topaz near high temperature like near a heater or inside a hot car can create flaw in the stone. Cleaning with ultrasonic cleaners can also create flaw in the stone. It is best to clean the topaz with warm water and soap.
Only buy topaz from a reputable dealer. As a precaution, any dealer using the terms "Bohemian Topaz", “Spanish topaz" or "Nevada topaz" may not be reputable.
About the Author: Kevin
Chang. To learn more about topaz gemstones and other loose gemstones, please visit http://www.gemstoneeducation.com Article Source: http://EzineArticles.com/?expert=Kevin_Chang
http://EzineArticles.com/?Gemstones-101---The-Topaz&id=682131
|
