Where is topaz from

After faceting they were irradiated and heated to produce the blue colors. Blue topaz with a color produced by treatment is the most common color of topaz in commercial jewelry today - and its low price makes it incredibly popular.

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 be sold to the public in jewelry. In the United States, the Nuclear Regulatory Commission requires all irradiated gems and gem materials to be securely stored until their radioactivity decays to a level that is safe for manufacturing and sale. This is done to protect employees of the gem and jewelry industry and the jewelry-buying public.

All companies who distribute newly irradiated gems in the United States must be licensed by the Nuclear Regulatory Commission. They must also conduct radiological surveys of all materials in secure storage to be sure that no gems are released until their radioactivity declines to a level that will not pose any health risks.

The Nuclear Regulatory Commission has detailed information about irradiated topaz and other gemstones on their website. They also have answers to frequently asked questions. Two answers that we believe will be of interest to our readers are quoted in the box on this page. You can read the rest by visiting the NRC website. These valley fills were once thought to be deposited by water, but now many of them are believed to have been deposited by ground surges of hot ash.

The Topaz Mountain Rhyolite has many vuggy areas, which often contain champagne-colored topaz crystals. USGS image. Placer Topaz: Topaz has a high specific gravity, and because of that it is commonly concentrated by stream currents into placer deposits.

Much topaz has been produced from placer deposits in Brazil and Nigeria. The topaz pebbles in the photo above are from Brazil and were rounded and frosted during stream transport.

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 a pegmatite , or in the vesicles and intergranular spaces of rhyolite. These topaz crystals grow during the late stages of magma cooling and while degassing releases the fluorine necessary for topaz crystal growth. Precipitating in cavities, topaz sometimes develops nicely formed crystals.

These crystals can have excellent clarity and can be used as a gem material. Many mineral collectors enjoy collecting gem-quality topaz crystals because they have the value of an excellent mineral specimen plus if they are of rare color the value of a gem material.

Topaz is also found as water-worn pebbles in stream sediments derived from the weathering of pegmatites and rhyolites.

These are often produced by placer mining. 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 topaz is produced in the state of Minas Gerais in southeastern Brazil.

The Ouro Preto and Capao mines have been the most important sources of yellow, orange, pink, red and violet topaz crystals for the gem and mineral specimen markets. Brazil is also the leading producer of colorless topaz, much of which is heat treated and irradiated to produce the colors of Swiss blue and London blue. Pakistan is a smaller but noteworthy source of pink, red and violet topaz.

Sri Lanka is a very important source of colorless topaz. In the United States, some topaz is produced in Utah , where it was named the state gemstone in 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. Despite the confusion, the name stayed!

The first yellow crystals modern-day topaz stones were discovered in Germany in , and then in , a large gem was found in Brazil. However, it seems that mix-ups seem to go hand-in-hand with topaz. The huge stone was originally believed to be a diamond and was quickly fixed in place on the Portuguese crown.

The gem was later identified as a topaz rather than a diamond — but kept its place on the royal headwear regardless. Huge topaz crystals have been found in the past in Ukraine and Brazil.

Whilst natural blue topaz does exist, it is extremely rare. More often than not, blue topaz is man-made via treatments. Shop Blue Topaz Rings. London Blue Topaz is believed to signify healing and calming. This could be the perfect gem to say sorry or prove how much you care for someone.

Blue topaz is created from colorless or very lightly colored topaz. The topaz is irradiated and heat-treated to bring out the blue color. Experts apply different levels of radiation to create various shades of blue. After the raw topaz is extracted from the earth and cut, it is irradiated to brown and then heated to sky blue.

This enhancement process is permanent. Blue topaz is produced by taking colorless topaz and subjecting it to irradiation and heat, producing a variety of saturation from deep blue to the lighter pastel shades. The treatment is permanent and the value is reasonably consistent so the selection of the most preferable becomes a matter of taste.

When chromium replaces aluminium in the crystal structure of topaz, the crystal appears to be pink or red. A crystal with a chromium impurity and a yellow coloured centre would be an orange topaz.

Topaz crystals have perfect cleavage, which means that it tends to break along certain plains, perpendicular to the long axis of the crystal. For this reason, topaz is quite fragile, even though it has a hardness of 8, and is often found in sections, rather than whole crystals.

Hardness is the resistance to being scratched, but the ability to resist breakage is called tenacity. Because topaz is so fragile, it is difficult to cut and set.

Some topaz crystals from Brazil are huge, as big as boulders and weighing kilograms. The American Golden Topaz is a famous gemstone. It now weighs 4. The El Dorado Topaz , also from Brazil, was discovered in It weighed around 36 kg, but after being faceted into an emerald shape and polished, was reduced to 6.

It is the largest faceted stone in the world. Topaz can be a raw material for making refractory materials. These materials retain their strength at high temperatures, so can be used in furnaces, kilns, incinerators, and reactors.

They are also used to make moulds for casting glass and metals. The steelmaking industry uses most of the refractory materials produced. Topaz can also be used as a raw material in the production of fluorine compounds, and in ceramic and glass manufacture. The name topaz has been used for any yellowish gemstones for at least two thousand years. Gem traders did not know that these yellowish stones were actually different minerals until about two hundred years ago.

Gem traders recognised that quartz, beryl, corundum and olivine all had yellow variants and were not true topaz and that topaz could be other colours not just yellow. In addition, the island Topazios, after which the gemstone has been named, never produced topaz, but was a source of peridot, or olivine often confused as topaz. The island is now called Zabargad Island.