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Topaz Misnomers
The name “topaz” has often been used incorrectly or inappropriately in conversation and commerce. These incorrect uses of a name are called “misnomers”. Misnomers can be used in three ways: The word topaz is used in all of the above ways and perhaps more. A list of topaz misnomers is provided below with a brief…
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Sources of Topaz
Topaz is found in many locations worldwide where rocks like pegmatite and rhyolite are formed. Here, topaz is usually a minor mineral in terms of quantity, and a secondary mineral in terms of its time of formation. Brazil has been the world’s most important source of topaz for decades. Almost all of the world’s fine-quality imperial…
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Geologic Occurrence of Topaz
Topaz has a chemical composition of Al2SiO4(F,OH)2. The fluorine in its composition is a limiting factor on its formation. Fluorine gas in concentrations high enough to form minerals only occurs in a few geologic environments. Most topaz grows as crystals within the veins and voids of igneous rocks. This topaz is found in the cavities of…
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Radioactive Blue Topaz?
The type of irradiation used to transform colorless topaz into blue topaz can cause the irradiated material to become slightly radioactive. Fortunately, the radioactivity level of the topaz begins to decline as soon as treatment is complete. It eventually declines to a level that is safe for the topaz to be handled during manufacturing and…
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Topaz Treatments
Today most topaz offered in department stores and mall jewelry stores at low to moderate prices has been treated in a laboratory. Colorless topaz can be heated, irradiated, and coated with thin layers of metallic oxides to alter its color. Natural blue topaz is extremely rare and is usually pale blue. Almost all of the…
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Use of Topaz as a Gemstone
The name “topaz,” and variants of the name in other languages, have been used for yellowish gemstones for at least two thousand years. At that time yellowish gems were called “topaz” in many parts of the world. Many of the earliest gem traders did not realize that these yellowish stones were actually different materials. Then, about two…
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What Color is Topaz?
Topaz occurs in a wide range of natural colors; however, most natural topaz is colorless. The most highly regarded colors are the reds and pinks, which receive their color from trace amounts of chromium. Chromium is also responsible for the color in violet and purple topaz. A variety known as “imperial topaz” is especially valuable…
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Physical Properties of Topaz
One of the best-known physical properties of topaz is its hardness. It has a hardness of 8 on the Mohs hardness scale, making it the hardest silicate mineral. Every student who takes a physical geology course learns about the exceptional hardness of topaz. Diamond, corundum, and chrysoberyl are the only commonly known minerals that are harder than topaz. Topaz occurs in a…
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Topaz – The November Birthstone
Topaz is the original modern birthstone for the month of November. Its status as a traditional birthstone contributes significantly to the gem’s popularity and is the reason behind many sales. Topaz jewelry is sold in almost every jewelry store in the United States. In 1952, Jewelers of America made a few modifications to the list of modern…
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What is Topaz?
Topaz is a rare silicate mineral with a chemical composition of Al2SiO4(F,OH)2. It is best known for being these four things: Topaz obtains much of its popularity from its beautiful colors and its status as a birthstone. Natural topaz colors include rare and valuable yellow, orange, pink, red, purple, and blue. The most affordable and frequently purchased are…