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TOPAZ

BY: VERNIE SORIANODESCRIPTIONTopaz is the silicate mineral of aluminum and fluorine with the chemical formula of Al2SiO4(F,OH)3 (Aluminum silicate fluoride hydroxide).It is used for the standard hardness of eight in the Mohs Hardness Scale.It is a common gemstone that has been used for centuries in jewelry.It is hard 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 banged hard.Compared to other minerals, topaz is relatively resistant to weathering and stream abrasion.It is the birthstone for the month of November. In Middle Ages, wearing topaz was believed to heal the body, cure insanity and prevent death.

Colors of topaz include: clear, white, yellow, brown, orange, pink, blue, green and gray. The color in which the topaz is most commonly found is yellow. Blue topaz is a very popular gemstone but this color is rarely found in nature. Today, most of the blue topaz being sold as a gemstone has been treated. To produce blue topaz, some dealers irradiate clear topaz then heat it to produce a blue gemstone. A small amount of topaz occurs naturally as pink and red crystals. These are the most expensive colors of natural topaz.Brown topaz can sometimes be heat treated to produce a pink stone.Two other colors of topaz are seen in the gemstone market. One is a green topaz that has been produced by diffusing chromium into the outer surface of the stone. Another treated stone is sold under the name "mystic" topaz. This is a stone with an iridescent appearance that is produced by vapor coating the surface of clear topaz with titanium oxide.

BACKGROUNDThe topaz has been known for at least 2000 years and is one of the gemstones which form the foundations of the twelve gates to the Holy City of the New Jerusalem.According to Pliny, the name "topaz" is usually derived from theGreek,Topazos, which is the ancient name ofSt. John's Islandin theRed Seawhich was difficult to find and from which a yellow stone was mined in ancient times.Alternatively, the wordtopazmay be related to the Sanskrit word "tapas" meaning "heat" or "fire". The Egyptians believed that topaz was colored with the golden glow of the sun god Ra. The ancient Greeks believed that it had the power to increase ones strength and make its wearer invisible in cases of emergency. The Romans associated topaz with Jupiter, who is also the god of the sun.

SOURCESTopaz sources are distributed around the world. It is found in the gravel deposits along with other gemstones in Sri Lanka, Madagascar and Myanmar because of its hardness and specific gravity.The world's entire supply of imperial topaz is mined from two mines, the Vermelhao mine and the Capao mine, at Ouro Preto in Brazil, where some experts say the deposit will be exhausted very soon. The most important source for topaz is the state of Minas Gerais in Brazil. Currently, Brazil is the leading topazprovider in the whole world.Some topaz is also mined in the United States, in the Pala region of California, and in the Rocky Mountains. Natural pink topaz is found in North Pakistan and Russia.Pale topaz that can be enhanced to blue is found in Brazil, Sri Lanka, Nigeria, and China. Other sources are in Pakistan, Afghanistan, India, Japan, Russia, Ukraine, Australia, Namibia, Zimbabwe, and Mexico.

APPLICATIONS IN INDUSTRYTopaz is widely used in making jewelry. You can get it on earrings, rings, necklaces, brooches, bracelets, pendants, pins and cufflinks which can be worn by both males and females.The blue, orange, and pink colors are most often cut as gemstones, and colorless Topaz is becoming increasingly popular as an inexpensive Diamond simulant. Gigantic gems and faceted spheres are cut from huge flawless crystals, and these make exquisite and exclusive collector items. Topaz is rarely cut into cabochons.Most of us tend to think of gemstones used strictly in a jewelry capacity, but lesser quality stones can be ground down for industrial uses as well. Topaz is frequently used as an abrasive in many products, including scouring pads and knife sharpeners. It's even used in sanding products and grinding equipment.

METHOD OF PROCESSING1. MINING PROCESS

Topaz is typically mined through a process called "surface mining. There are five different types of surface mining: strip mining, open pit mining, dredging, highwall mining and mountaintop removal mining. Topaz can be collected through underground mines as well. In most forms of surface mining, heavy equipment and large machines are used to extract the mineral.When a seam of the topaz is mined, the process used is strip mining. It involves removing a strip of overlying rock and soil first. Open pit mining, as the name implies, involves extracting minerals from the earth through an open pit.Dredging is used to collect underwater minerals by clearing or enlarging the waterways of boats. Highwall mining involves penetrating a cold seam through the continuous use of a miner that is propelled by a hydraulic push beam mechanism.Explosives are used to blow the tops off mountains in a process called mountaintop removal mining. This type of mining is used primarily in the Appalachian coal fields of West Virginia, Kentucky, Virginia and Tennessee.METHOD OF PROCESSING2. Once the topaz has been mined, it is polished. This gem is polished with tin laps and tin lead laps that are charged with diamond or aluminum oxide. This same method is used to polish gems like chrysoberyl, garnet, peridot, tourmaline and beryl. 3. Finally, the gem is put into jewelry and sent to a jewelry store. The gem can also be sold by itself, without having been put into jewelry.REFERENCEShttp://www.mineralszone.com/minerals/topaz.htmlhttp://www.gemstone.org/index.php?option=com_content&view=article&id=100:sapphire&catid=1:gem-by-gem&Itemid=14http://jewelry.lovetoknow.com/What_is_Topaz_Used_Forhttp://geology.com/minerals/topaz.shtmlhttp://www.minerals.net/gemstone/topaz_gemstone.aspxhttp://www.gemsbrokers.org/gemstone/gems_and_gemology/topaz_sources.htmhttps://en.wikipedia.org/wiki/Topazhttp://yourbirthstones.com/november-birthstone/#more-145