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Showing posts with label Tourmaline. Show all posts
Showing posts with label Tourmaline. Show all posts

Saturday, March 26, 2011

Those Color Change Stones ! Surprise Someone !

Wear the same necklace or earrings in the daytime, or at night, in florescent lighting or incadescent lighting and make people think you have a whole wardrobe of jewelry. Most people that have ever had anything to do with gemstones are aware that certain stones change color under varying light conditions. Many of these color differences are apparent only to the trained eye, but the so-called "color-change" gems exhibit this tendency to such a dramatic degree that it is obvious to even the untrained eye.
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For most Alexandrite is the everyday example and all know the saying : Emerald by Day - Ruby by Night", greenish under daylight or flourescent light and reddish under incandescent light.


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Color-change Garnet changes from bronze in daylight to a rose pink under incandescent light.

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Although most Sapphires have some color change to them and why good Sapphire markets only trade during daylight, the color-change Sapphire exhibits a range of many different color changes. Most color change Sapphires are blue under natural light and purple under incandescent indoor lighting.

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But there is a fourth color-change stone that in sizes from 5 carats up, exhibits a raspberry red to leaf-green color change as dramatic and complete as that of fine Alexandrite. So why doesn’t this Turkish delight get the respect it deserves? It's true name is Turkish Diaspore. But recently it has been given a new name - Zultanite. This marketing name - Zultanite—a deliberate misspelling of Sultanite which was already the registered trade name for another Turkish product. One would think Turkish-sounding names like Ottomanite or Caliphanite would have done a better job of invoking Turkish history, than substituting a “z” for an “s”? In any case, Zultanite Gems LLC, based in Fort Lauderdale, FL, has been doing its best since 2005 to capture attention for this inexpensive, all-natural rare gem with a hardness between 6 ½ and 7, and minuscule yields of 3 percent from the rough. Maybe the fact that this company has the sole rights to mining of this gem at its only known source, some 4,000 treacherous feet up in the mountains of Anatolia, prevents others from joining the company in the promotion of this gem.

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So take a look at these pictures above and note that unlike other color change gems that need separate lighting environments to show their color states, this highly pleochroic gem can perform multi-colored wonders when cut with that purpose in mind.
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One other stone that must be mentioned at this point because of it's popularity is Zandrite. This stone is a type of synthetic glass that was developed by a major glass manufacturer. One of the developing scientists realized that there was a gemstone marketing application possible and started the ball rolling to create a new synethic gemstone sensation. Based on the reaction from the public, he was quite successful. Since Zandrite changes color is the reason for it being named Zandrite ... sort of a cutesy take-off on the name of Alexandrite. It was most likely an effort to fool the unknowing consumer who might mistake the Zandrite name with the Alexandrite name and think they were getting the real thing for pennies on the dollar compared. Zandrite is a man-made lab created stone that was specifically produced to mimic Alexandrite, an imitation not a synthetic, but in many settings is a beautiful gemstone in its own right. This mimicing went over so well, that there are now other color-changes available in Zandrite gems.
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And not to be left out, is the Russian Lab-created Alexanderite. Synthetic lab grown (created) Chrysoberyl Alexandrite gems many times exceed natural Alexandrites in clarity and color change, and since they are 'real' Alexandrites grown from seed stones, confuse even some of the best gemologists and jewelers. Synthetic lab grown gemstones are like comparing a rose grown outside to one grown in a greenhouse, both are the real thing - BUT ! Also be cautious when buying lab-created Alexandrite, because many dealers indiscriminately use the term imitations and are making reference to color-change Corundum, which Alexandrite is a member of the family, instead of stating it is synthetic Alexandrite. A fine line but a distinction that should be made and disclosed to customers.

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Additional Info --- I have been informed I left out color-change Tourmaline. I was unable to find any reference to such, but do remember hearing about it the Tucson Gem Fair. I do not have one or have I ever seen one. If anyone can provide a picture showing both colors I would definitely appreciate it.

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Thanks to the ISG, Zultanite Gems LLC and others for information and pictures of color-change gemstones.
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Wednesday, September 15, 2010

The Trapiche Gemstones !

Everyone should always keep their eye open for some of the neatest and fairly rare gemstones in existance --- the Trapiche Gemstones ! The Spanish word trapiche was used in Colombia with a literal translation that means 'wagon wheel'.
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It was and still is applied to a rare form of Emerald that has inclusions aligned along the edges where the crystal faces meet, which causes the stone to literally look like a wagon wheel. The most famous and best known is the 'Trapiche Emerald'.
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A Trapiche Emerald, found only in Colombia at Coscuez, La Peña in the celebrated Muzo mining district
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But......the trapiche 'wagon wheel' formations can indeed occur in other types of gemstones, i.e. Ruby, Sapphire, Tourmaline and particularly in a form of Andalusite. So the term 'Trapiche' must be clarified by adding the name of the Gemstone along with it.
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For insatnce Trapiche Ruby, of which there are two distinct types, one with the carbon 'wheel' from Viet Nam and the second with the lighter colored 'Calcite' or 'Dolomite' wheel' from the Mong Hsu region of Myanmar (Burma).
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A Trapiche Sapphire, probably of Burmese origin.
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A Trapiche Tourmaline, of this green variety, can be obtained from the Kavungu mine in the vicinity of Jivunda southeast of Mwinilunga in northwestern Zambia.
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A Trapiche Andalusite, called Chiastolite, has the same kind carbon spokes as the Emerald and Ruby. This particular form of Chiastolite is found in areas around Georgetown, California. It is also known to many as "The Cross Stone" in religious circles.


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And I have been told there is a Trapiche Garnet, but have never seen one or even a picture of one, so definitely something to look for.
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Pictures from own collection and those of some close friends. The locations indicated are where these particular speciems originated from.
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Tuesday, July 7, 2009

Maine's "Tourmaline" !


Tourmaline was the first gemstone mined in the United States by miners other than prehistoric man or Native Americans. Tourmaline mining began at Mount Mica, Maine, in 1822 and, with starts and stops, has continued to the present day.
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Over the years, mining operations on Mount Mica produced hundreds of kilograms of tourmaline. Museums and private collections around the world contain outstanding examples of tourmaline from the deposit. The largest reported crystal from the site apparently is one that is 39.4 centimeters long, 17.8 centimeters wide, and weighs about 14.3 kilograms. Apparently, a flawless, blue-green 256-carat stone is the largest cut stone from Mount Mica. Mount Mica may have been the first tourmaline producer in Maine, but it is by no means the largest. Newry Hill, a spur off Plumbago Mountain, or more specifically the Dunton Mine on Newry Hill, is the most prolific tourmaline producer in Maine. Other mines and quarries in a three county area produce gem- and specimen-grade tourmalines. The level and type of activities at each mine or quarry vary from year to year. Currently, most of them are open to hobbyist or professional collectors for a fee or with the owners permission.
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Maine tourmalines come in a wide variation of colors, deep grass green to light green to yellow-green to blue green. They are also found in all shades of red, from pink to deep red, and blue-green to light blue to deep blue, and as colorless crystals. The State's mines also produce bicolors and watermelon crystals. The colors can be very fine and some believe that Maine tourmalines set the standard for non-chrome green tourmaline. Although the State Legislature has never officially declared the Tourmaline the state gem, rock or mineral, ask anyone who knows about Tourmaline, and most would tell you it is the State gemstone.
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Sunday, April 26, 2009

QUARTZ with "Inclusions"

Pieces of 'Clear Quartz' with inclusions can be a facinating study. I am not about to attempt to list or go into the many types of inclusions that can occur in Quartz, because for each one I mention, someone will be able to name a dozen more. For the purpose of this article we will talk about 'Rutilated Quartz', 'Dendritic Quartz' and 'Tourmalinated Quartz'. I will also present some pictures I have been provided of some other interesting included Quartz pieces.
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A piece of clear crystal Quartz known as a Sceptor.



Dendritic Quartz. The stains are found in microscopic fissures that cause them to branch out like tree limbs or fern like inclusions. Of course in nature no two things are alike, making each gem one of a kind. Like most of the included quartz, the primary sources of Dendritic Quartz are Brazil and Africa, but some have been found in the western United Satates and Arkansas.

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Rutilated Quartz. Rutile is a major ore of titanium, which is a metal used for high tech alloys. It often forms needle-like crystal inclusions inside the Quartz crystal. This form of quartz looks like small bars of imbedded gold. Rutile is a 6 on the Mohs scale whereas Quartz is a 7. Because of the difference in hardness between the two materials and because of the way rutile forms inside, this can be a difficult stone to attain a smooth surface without pits. Most Rutilated Quartz is found is Brazil, Pakistan, Kazakhstan, Madagascae, Brazil and several locations in the United States.

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Tourmalinated Quartz. As pointed out many minerals may be found as inclusions in quartz. When Tourmaline is found within quartz, the quartz is known as "tourmalinated". Most of this variety of Quartz is found in Brazil but large pockets have also been found in California.


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Here are some pictures of some other types of included Quartz.
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Quartz with included Pyrite........ Quartz with included Gilalite

Quartz with included Lepidocrocite and Hematite

Lodolite is a term used for a varity of Quartz with included minerals from Minas Gerais, Brazil. The colorations and patterns come from three main types of minerals, Chlorite, Iron, and Calcite.
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