Texas Topaz Day - Mason, Texas - Mar 24-25, 2012

This coming weekend the Southwest Gem and Mineral Society in San Antonio and the World Gem Society invites everyone to come to Mason, Texas, to join in the Texas Topaz Day festivities on Saturday, March 24th, followed by the Texas Faceters Guild Seminar Day on Sunday, March 25th. Mason, Texas, right in the heart of the Texas Hill Country is located in some of the most interesting geological formations to be found anywhere in the world. The festivities and events start at 10:00 am on Saturday and run all day with gemstone cutting and faceting demonstrations, jewelry and arts shows, and contests and music events to cap off the day. Then on Sunday you can join the Texas Faceters Guild for a day of learning about the latest in gemstone cutting and faceting. From novice to expert all are welcome.

The Blue Topaz was adopted as the Texas State Gemstone as a result of legislative approval on March 26, 1969. Petrified Palmwood was also named the State Stone by the same legislation. This Swiss Blue Topaz just above has been given a special cut to show the Texas Lone Star. A limited supply of these will be available over the two days in Mason, Texas.

Topaz occurs naturally in many colors including blue, orange, brown, green, pink, beige and red. Naturally occuring Blue Topaz is quite rare. Colorless topaz, the most common variation, can be treated by irradiation to produce a wide range of shades of blue, which are known as Sky Blue, Swiss Blue and London Blue. This treated, Blue Topaz is one of the most popular and widely used of all gemstones. London Blue is the most famous and most highly prized, but takes over 18 months to produce. Radiation scares have centered around the process and lasting effects from the making London Blue Topaz.

Some clear topaz crystals from Brazilian pegmatites can reach boulder size and weigh hundreds of pounds. Crystals of this size may be seen in museum collections. One famous Topaz is The Topaz of Aurungzebe and weighed 157.75 carats. Colorless and rarely light-blue varieties of Topaz are found in Precambian granite in Mason County, Texas, within the Llano Uplift in the Streeter, Grit, and Katemcy areas. It is usually found in streambeds and ravines but occasionally can be located atop the ground. Currently, only three Mason County ranches offer the public the opportunity to go Topaz hunting. They charge by the day, you keep what you find. You can enjoy Topaz hunting throughout the year except during the months of November, December and early January, when the ranches are closed for the deer season. There is currently no commercial mining of Topaz in that area. The natural Blue Topaz found in this area is the scarest of all the Topaz varieties.

Topaz is also the Birthstone for the month of November.

So as not to confuse the Lapidary enthusiasts, the Official State Rock of Texas is also Petrified Palmwood.
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RUSH to PLUSH ! - Oregon Sunstone !

Rush to Plush for Oregon Sunstone UPDATE! This event is open to everyone...

We have received many inquiries about the ISG Rush to Plush 2011 and who can attend. We want to stress that the following people can attend:

Everyone!

If you hear about it, you can attend it. Some folks are thinking that you have to be an ISG Student or Graduate to be a member of the ISG Community. This is not true!!!

If you read this newsletter and love gemstones, you ARE a member of the ISG Community. You can formally join us by clicking on the link below. All are welcome to join the ISG Community Home.

Join the ISG Community Home

But if you love gemstones and enjoy reading this newsletter, you are a member of the ISG Community.

And again....Every Living Soul on Planet Earth is welcome to attend the ISG Rush to Plush 2011 Events. For more information please click on the link below.

ISG Rush to Plush 2011


Led by Robert James


Join the ISG Community. If you want to learn, share, and grow in the gemstone and jewelry industry we invite you to join us in the ISG Community. Just click on the link below to join the ISG Community Home.

Join the ISG Community Home

Hydrophane Opal - see if you have one in your collection !

The stone in the picture is called a Hydrophane Opal. It quite literally soaks up water like a sponge, and does some very unique things with the water. Just sitting around in the open air it is pretty, but when you start letting it do its thing .. soaking up water .. things really start to happen. This particular variety of Opal is from Ethiopia and is sometimes known as 'Welo Opal' and also by other names. This stone offers a beautiful play of color that is made more intense after it has been submerged in water. The water does dry out after a time and that allows the opal to revert to its original state, thus making this opal almost a chameleon for colors.

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Ethiopian Opal is quite unique and different from the more common Australian and Mexican opal. Not many people are familiar with or as are yet familiar with this variety of Opal. However the Ethiopian Opal is, in a sense, an old gemstone. In 1939, an anthropologist found evidence of the use of the Opal by early man in a cave in Kenya. So there must have been an Opal deposit somewhere on the Africa Continent. Finally in the mid 1990s, the Opal was re-discovered in Africa by a mineral engineer named Telahun Yohannes in the Yita Ridge, Shewa Province, Ethiopia. and he started mining it.

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One of the most interesting features of the hydrophane Opal is directly due to this ability to absorb liquids and dry out. The stones have been successfully dyed using this ability, but more important is what is believed to be natural oxides in the stone that are due to the absorption feature of the stone. Perhaps the most interesting part of these Opals is the huge variety of colors and intensities of colors based on the variable of lighting. Standing in one place they will look one way, turn around in the room and they change into something entirely different. Very strange and wonderful stones that are sure to become a major player in the Opal market.
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Be cautious of someone selling Ethiopian Opal jewelry and it is advertised as an antique or vintage piece. There is no such thing. As of 2011, this opal had been on the market for only about 15 years. In December 2008, another Opal deposit was found in Gondar, Welo Province, Ethiopia. As of October 2010, most Ethopian Opal roughs come from Welo. The mining in Shewa seems declining.

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Many thanks are due Robert James at the ISG and ISG member Alicia, for their information about this specific Opal.

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Pearls - Looking at the inside !

The first thing to point out is that there are several types of oysters and mollusks that are used to produce pearls, both salt-water and freshwater. I am not going to go into the different kinds of pearls in this discussion, just what the inside of all of them basically look like. Borrowing some photographs from the International School of Gemology (ISG) where gemology is taught based on actual specimens of gemstones: natural, synthetic and organic, rather than from pictures in books, we will take a look at the inside of a pearl For this discussion, the internal differences between a salt water Akoya cultured pearls and a Chinese freshwater cultured pearl will be looked at. At the end, a new surprising find will really make one wonder.

Above is seen a 5mm pearl purchased as an Akoya cultured pearl. Notice that it is uniformly round from the seed all the way out to the outer nacre layer, which is the thin line you see at the very edge of the pearl. What was quite remarkable about this pearl is that the center of the pearl is a hollow plastic looking bead, not the Mississippi mussel shell bead that was expected. You can see the circular structure of the Akoya cultured pearl with the bead and resulting layers being rather uniform from center to outer nacre layer.

Now above you see a freshwater cultured pearl from China . These are called non-nucleated pearls since they are started with a ball of tissue rather than a pre-formed bead. The picture is quite graphic to show that the center of this pearl is a somewhat organic looking mass of old tissue rather than a well formed starter bead as seen in the Akoya pearl. These pearls have been back lit to allow one to see the difference in formations, which is rather pronounced and graphically demonstrates the basic difference between the salt water Akoya and the freshwater pearl.

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A question was asked that perhaps since the freshwater pearl was started by what is basically a ball of tissue, that should there not be some kind of hollow place in the center of a freshwater pearl as the tissue degenerates during the growth process? And sure enough, when the viewing angle is changed on the freshwater pearls, one can see hollow places in the pearl as seen in the pictures below of a half drilled 5mm freshwater pearl.

Thus these pictures show what would be seen if you dissect one of those expensive little jewels you have on that string of pearls you got as a gift.

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Now for the surprise. How about opening up one of those very expensive Tahitian South Sea Pearls which are known for their excellent quality and thick nacre layer. But what’s really inside one of those Tahitian pearls? Well, one was cut open and to the surprise of everyone, what was found is almost beyond comprehension !

The center is a plastic bead. Apparently someone has found out how to use plastic instead of natural material to get the Pearl to form.

And taking it one step further, perhaps a reused piece of plastic for the starter bead. Why the multiple holes in the starter bead? Was the pearl farmer recycling plastic? Why place a used, multi-drilled plastic starter bead inside an oyster to make what could turn out to be a very expensive South Sea Tahitian Pearl in the first place?

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But then again, it is this type of perplexing problems that is what makes gemology so much fun and of interesting experiences. A lifetime of learning and sharing the wonders of the earth.

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Again thanks to the ISG for the use of pictures and information.

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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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OPAL - Australia's National Gemstone

Based on several requests have decided to do a Blog on Opals. However this specific BLOG deals with Australian Opals. Many thanks must go to the Jewelers Association of Australia for their information and pictures. There are other major varieties of opals not covered here, Mexican Fire Opals (transparent to translucent opals with warm body colors yellow, orange, orange-yellow or red and they do not show any play-of-color), Peruvian Opals (semi-opaque to opaque blue-green, green, blue or pink stone found in Peru which is often cut to include the matrix in the more opaque stones. They do not display pleochroism), to name a couple. Other varieties of opal can also be found in Slovakia, Brazil, Ethiopia and the Northwest and Southwestern United States with new finds now reported in China.

The Australian Opal. Nature has captured all the colors of the spectrum, displaying them in an infinite variety of shades, patterns, and brilliance and locked them into this rare stone. Opals lie dormant in the earth until a miner clips the edge and light reaches the gem exposing the most beautiful dancing displays of color. This ‘Play of Color’ is the basis for the opals beauty. It is unique in the world of gemstones. It originates from the breaking up of white light due to the three dimensional spherical shaped microstructure of the silica partials inherent in the opal. Similar color phenomena can be observed when oil lies on water. Opals occur where silica gel fills small fissures or voids in the earth. A large portion of Australia’s inland was once covered by a sea, leaving deposits and creating an environment suitable for the formation of the opal. As the cellulose of the tree wood decays, it leaves empty cells in the wood. As the silicon rich water seeps down into the void, it eventually dries out and leaves the silicon behind to form opals. Some of the water is retained by he silicon dioxide...which is why opals contain so much water. The silicon forms as small rows of round spheres that create the ‘Play-of-color’. Natural Opals are divided into categories to distinguish the location where mined and the specific variety of Opal.

BLACK OPAL is the most valuable and comes mainly from Lightning Ridge. High quality stones are very rare; this type is easily distinguished by the blackness of the base or background body tone.

BLACK CRYSTAL OPAL is mainly mined at Lightning Ridge. These black opals show a degree of transparency, the colors are often brilliant and can appear to come from within the depth of the gemstone. Good black crystal opals are extremely rare.

DARK OPAL comes from all the fields and is desirable because the colors are generally more brilliant, due to the dark background highlighting the colors. Good specimens of this type of opal mainly come from Mintabie and Lightning Ridge.

LIGHT OPAL is usually found at all opal fields but the bulk of the better material comes from the South Australian fields of Coober Pedie and Andamooka, although the first material was mined at White Cliffs. Some light opals are so light they are called White Opals (2nd picture above).

CRYSTAL OPAL embraces opals which are transparent or very translucent and in the better quality stones shows a distinct and very bright play-of-color. This type of opal is found in most Australian opal fields.

BOULDER OPAL is composed of opal naturally occurring on its host rock. It is mined predominantly in Queensland. It is easily identified because when cut, the host rock if left on the sides and/or back of the opal. Boulder Opal may be light, dark or black within the host rock. This type of opal in cabochon settings, has become very popular in the past few years, especially those stone that have the host rock all around the ‘window’ of opal in the center of the stone.



MATRIX OPAL comes in two types in Australia.

-BOULDER MATRIX OPAL is usually found in Queensland. The opal is intimately diffused with the host rock (usually ironstone so is magnetic), which is quite obvious in the presentation face of the stone.

-MATRIX OPAL from the Andamooka area has opal internally diffused throughout the host rock, a sandstone, which is often porous and can be treated, turning the material dark, resembling black opals.

NATURAL OPALS are the complete opal cut and polished as one piece. These can be very fragile and easily damaged when worn.



COMPOSITE NATURAL OPALS consist of a natural opal laminate manually cemented or attached to another material. There are three main types.

-DOUBLET OPAL is a composite of two pieces where a slice of natural opal is cemented to a base backing material.

-TRIPLET OPAL is a composition of three pieces where a thin slice of natural opal is cemented between a dark base material and a transparent top layer, usually of quartz or glass.

-MOSAIC CHIP OPAL is a composition of small flat or irregularly shaped pieces of natural opal cemented as a mosaic tile on a dark base material or encompassed into resin.

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There are three (3) specific other Opal types that also come from Australia that I hope to gather further information on and be able to post a Blog in teh near future on them - Andamooka, Koroit and Yowah Opals. Check out the Opal Forum at

http://forums.opalauctions.com/viewtopic.php?f=3&t=1647&start=180

for informatin on these Opals.

SYNTHETIC and IMITATION OPAL has become a real problem worldwide, but not a problem in Australia. Australian law deals harshly with anyone making or selling synthetic or imitation opals and the few retailers who have them, will have them so marked and inform purchasers of this fact. You will see very few within Australia.

For our budding gemologist and geologist, opal is a mineraloid, it is an amorphous SIO2 - NH2O (hydrated silicon dioxide). The water content is usually between three and ten percent, but can be as high as 20%. It is a 6 on the Mohs scale of hardness. Opal has a RI: 1.44 - 1.46 -- Birefringence: None -- Optic Character: None -- Specific Gravity: 2.10 average but varies based on amount of water contained in the stone.

Opal is the traditional birthstone for October and the state gemstone of Nevada.

Caring for your Opals
As with Pearls, the number one care item for Opals is to never have them on when using hair spray or wear them when doing rough work.
Solid Opals -- Opal is a soft stone, so it is important to treat your opal carefully In order to avoid damaging it. Remove your opal jewelry if there is a chance it will be scratched or broken (i.e. working in the garden, moving furniture, etc.) Many people believe solid opals can be damaged by water - however, this only applies to doublets and triplets. Solid opals are fine in water. In fact, most precious opals contain about 5-6% water. As a result, opal may crack if subjected to very dry conditions or rapid changes in temperature. Try to avoid very high temperatures or low humidity extremes, such as boiling water or zero humidity bank vaults.
Doublets & Triplets -- Caring for doublets or triplets is a little different to caring for opals. Because doublets and triplets consist of multiple layers glued together, prolonged exposure to water will eventually cause lifting between the layers and the infiltration of water. A doublet or triplet will take on a 'foggy' or grey appearance if this happens. This does not mean your opal will be ruined if you wear it in the shower once, or are caught in the rain. It takes prolonged exposure to cause water damage to a doublet or triplet.
Cleaning Your Opals
Solid opal should be cleaned gently with mild detergent in warm water and a soft toothbrush or cloth. Avoid bleach, chemicals and cleaners. Doublets & triplets may be wiped with a damp soft cloth and mild detergent, but should never be soaked or immersed. Never allow anyone to clean your opal in an ultrasonic cleaner, as the intense vibrations may cause cracking in a solid opal, and water penetration in a doublet or triplet. If your stone loses its shine or becomes scratched, bring it back to an opal cutter. After years of wear, small scratches and scuff marks cause an opal to lose its shiny polish and become dull looking. Professional polishing can bring new life to an opal which has become dull or scratched, and we can also check for claw damage and ensure the security of the setting.
Storing Your Opals
If you need to store your opal away for a period of time, simply place it in a padded cloth bag for protection and store it away. For longer storage periods, place your opal in a sealed plastic bag wrapped in cotton wool with a few drops of water just to be safe. The water is not intended to soak into the stone (as opal is impervious) but will prevent water coming out of the stone if it is exposed to very low humidity environments (for example, zero humidity storage safes).

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QUARTZSITE - A major prelude to Tucson 2010 !

Welcome to QUARTZSITE and Desert Gardens on the California - Arizona State Line.

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2010 Calendar of Events

January 01 - February 28, 2010 Desert Gardens-Gem & Mineral Show

January 01 - January 10, 2010 Tyson Wells Rock & Gem Show

January 09 - February 24, 2010 Main Event

January 15 - January 24, 2010 Tyson Wells Sell-A-Rama

January 16 - January 24, 2010 Sports, Vacation & RV Show

January 27 - January 31. 2010 Hobby Craft & Gem Show

January 29 - February 7, 2010 Tyson Wells Arts & Craft Fair

January 20 - January 24, 2010 Annual Pow Wow

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Then it is on to the Tucson Gem Fair 2010 during February !

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When its clear it is beautiful, but then the wind and sand rolls in.
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but the Show goes on, and the weather clears again.

There is plenty to see, masses of rock and minerals all over the place, inside and out.

Tables of new material, like Imperial Sarah Jasper,

or buckets of everything and anything imaginable,

and hugh slabs of Tigereye and TigerIron,

or maybe even some unknown wierd stuff.

How about a Geode big enough to stand or sit in
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and a few odd things also.

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Whatever you want, you could probably find it at QUARTZSITE and for sure at the following Tucson Gem Fair 2010. Many of the vendors at QUARTZSITE will move to Tucson as the various different shows open up there during the month of February.

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Pictures thanks to Ron, theimage1 and Quartzite.com.

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CRYSTALS IN THE RAW 7 !

Most of these raw stones most people have seen in Jewelry Stores as expensive gemstones mounted in expensive settings. Here is what they look like when fouind in the mines.

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Peridot Crystal from Arizona

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Morganite Crystal from California

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Heliodor Crystal (not the normal yellow-green variety) from Norway

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Green Chrysoberyl Crystal from Madagascar

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Aragonite Twin Crystals from Spain

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Thanks to several for providing specimens and to the Scapteguy for information on these crystals.
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CRYSTALS IN THE RAW 6 !

Addition crystals/minerals for viewing and starting to get into some lapidary slabs also as get polished up.

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Hematite Crystals from Morocco

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Cerussite Crystal from Morocco

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Amazonite Crystal from Colorado

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Chryscolla (Sanora Sunrise) Slab from Mexico

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Koroit Slab from Australia

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Thanks to several for providing specimens and to the Scapteguy for information on these crystals.
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