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Gallery 10  Agates, Geodes & Thundereggs

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Quartz geode, Kenfig Sands, Porthcawl, Bridgend, Wales, UK
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AD-123  Quartz & Hematite geode  $60

Kenfig Sands, Porthcawl, Bridgend, Wales, UK

7.5 x 7 x 2.6 cm.

Here we have a geode that very much resembles the more famous nodules from the Dulcote Quarry which is about 30 or so miles to the southeast. This ocean front location has been known for its geodes since at least the 1800's. According to H.T. De La Beche, in his Memoirs of the Geological Survey published in 1846, he puts forth the theory that these are weathered out of the seabed offshore and wash up on the beach.


Agate, Nowy Kosciól, Kaczawskie Mountains, Lower Silesia, Poland
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AD-239  Agate  $60

Nowy Kosciól, Kaczawskie Mountains, Lower Silesia, Poland

13.6 x 9.4 x 4.9 cm

Here we have a multicolored Agate from Poland's Kaczawskie Mountains. This Agate portion shows fine banding of orange and red hues. Nowy Kosciól is a classic Polish locality. Thunder Eggs such as these are highly prized by Polish Agate collectors and are rarely available outside of Europe.


Agate, Dulcote Quarry, Mendip, Somerset, England
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AD-240  Agate with Calcite and Hematite  $35

Dulcote Quarry, Mendip, Somerset, England

11.2 x 9.4 x .9 cm

A polished section of the variety of Agate dubbed “Potato Stones" by local collectors. Although there are many of these to be found in the hills & surrounding valleys, these once abundant nodules are almost never seen for sale these days. This is due to the fact that the main deposits are either located on private property or in quarries, making it almost impossible to collect specimens. The geodes and nodules from this classic location are much prized by collectors due to their colorful nature and endless arrays of circles and bands that make each one of these specimens truly unique.


 Agate geode with Quartz & Goethite, Rio Grande do Sul, Brazil
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AD-242  Agate geode with Quartz & Goethite  $45

Rio Grande do Sul, Brazil

14.7 x 8.4 x 6.8 cm

A geode comprised of light blue-colored Agate whose cavity is lined with small, sparkly Quartz crystals. Some of the Quartz crystals have overgrown sprays of the mineral Goethite resulting in a hemispherical shape. In addition to having been polished on its face, this specimen's outside has been polished as well.



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AD-175  Amethyst geode  $60

Nosy Varika, Vatovavy Fitovinany, Madagascar

11.5 x 8.2 x 5.0 cm

A very large and peculiarly shaped geode from a recent find in Madagascar. This specimen features a thin rim of Agate and a 4.5 cm vug lined with crystals of Amethyst.


Agate variety Carnelian, Chandler Mountain, Linn County, OR
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AD-238  Agate var. Carnelian  $50

Chandler Mountain, Linn County, OR

6.3 x 4.7 x 3.2 cm

Aa colorful example of the variety of Agate, Carnelian. The specimen has fine banding with colorful reddish-orange hues. The face of this specimen has been polished to the point that it has a mirror-like lustre.


Agate, Dryhead Agate Mine, Bighorn River Area, Pryor Mountains, Carbon County, MT
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AD-236  Agate (fluorescent)  $95

Dryhead Agate Mine, Bighorn River Area, Pryor Mountains, Carbon County, MT

10.5 x 8.7 x 3.1 cm

A very large & colorful sedimentary Agate from Montana. This specimen shows banding of red & several hues of orange surrounding a contrasting white core and encased in a coffee-colored matrix. The center portion of this agate also has good Fluorescence under SWUV light. Sedimentary Agates are formed in sediments as opposed to being formed by filling cavities in the rock during secondary processes in volcanic rocks. Dryhead" Agates, with their gorgeous colors and patterns locked inside the surrounding nodules, are prized by Agate collectors. The Dryhead Agates were named after many bison skulls found near the site. That was where the Native Americans were said to have run the bison over the cliff, killing many of them, and then arranging the bison skulls in ceremonial manner.



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AD-176  Agate  $50

Wave Hill, Victoria-Daly Region, Northern Territory, Australia

6.5 x 5.7 x 3.5 cm

A vividly-colored Agate from down under. this specimen features alternating copper-colored bands of Agate with a white core. this Agate has a good parallax. When a banded Agate forms with close alternating opaque and transparent bands, the light entering the Agate can cast an observable shadow from one opaque band onto the next. As the parallel bands change their perceived angle, the appearance of movement and perception of depth occur. The finer the banding, the more striking this effect is.



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AD-165  Agate & Quartz Thunderegg  $120

St. Egidien, Glauchau, Zwickau, Saxony, Germany

16.6 x 14.2 x 7.3 cm

A large specimen from Germany's premier thunderegg locality. The dense banded outer layers of deep-blue grades to a sky-blue core. This colorful thunderegg also features several small pockets of Quartz.


JChalcedony variety Jasper, Cairo, Egypt
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AD-106  Chalcedony  $60

Cairo, Al Qahirah Governorate, Egypt

7.8 x 5.9 x 2.1 cm.

When I was in Egypt in April 2010, I saw many nodules of Jasper and Chalcedony just lying around on the ground out in the desert near Cairo.  I wondered why no one has ever offered this material for sale.  In 2011, while at the Tucson show, I was fortunate enough to run into a dealer who had some of these nodules for sale.  I made a trade with him for two of these specimens.  It was explained to me that these colorful nodules are difficult to polish.  Jasper is a dense, opaque, microcrystalline variety of Quartz. Or more strictly; Chalcedony and is usually red, brown or yellow and coloured by Iron oxides.  I think I chose some good ones, with nice earth-colored tones and interesting banding.  One thing that I have noticed in my many years of collecting is that there is not too much available when it comes to Egyptian minerals.  These colorful Chalcedony nodules are sometimes called “Sahara Agate”.


Chalcedony, Agate and Quartz, Potato Patch, Imperial County, CA
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AD-126  Chalcedony, Agate and Quartz geode  $60

Potato Patch, Hauser Beds, Palo Verde Mountains, Imperial County, California

12.5 x 10.4 x 4.7 cm.

While once abundant, the days of easy digging at the Potato Patch are over.  This location has long been a favorite spot to collect and has been hit hard over the years.  These days there is not much to be found there.  This example of Chalcedony, Agate and a little cit of coarsely-crystallized Quartz is classic, older material that Agate & Thunder-egg collectors hold in high regard.



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AD-183  Chalcedony & Quartz Thunderegg  $60

Buchanan Beds, Harney County, OR

10.8 x 9.3 x 2.8 cm

Here we have a triple-chambered thunderegg from southeast Oregon. The green-colored rind combined with the white and red-hued interior makes for a nice contrast of colors. Multiple-chambered thundereggs are uncommon, more so triple, quadruple, etc... chambered nodules.



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AD-188  Agate & Quartz Thunderegg  $45

Dugway Mountains District, Dugway Range, Tooele County, UT

12.3 x 7.5 x 2.8 cm

This is one of the more attractive Dugway geodes that I've encountered. This lithophysae nodule features alternating bands of blue and white and cavities lined with drusy Quartz crystals.



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AD-198  Agate  $60

Amerzgane, Ouarzazate Province, Drâa-Tafilalet Region, Morocco

10.4 x 4.5 x 5.0

A blue-grey & white-hued Agate that exhibits a great parallax. This specimen could easily be mistaken for a Laguna Agate, that's how strikingly it “winks”. A parallax is an effect which is sometimes referred to as “winking”. When a banded Agate forms with close alternating opaque and transparent bands, the light entering the Agate can cast an observable shadow from one opaque band onto the next. As the parallel bands change their perceived angle, the appearance of movement and perception of depth occur. The finer the banding, the more striking this effect is.


Aqate and Quartz geode, Iraí, Alto Uruguai Region, Rio Grande do Sul, Brazil
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AD-118  Agate and Quartz geode  $30

Iraí, Alto Uruguai Region, Rio Grande do Sul, Brazil

6.2 x 5.4 x 4.5 cm.

While it is true that Agate specimens from Brazil are very abundant, every once in a while you find examples that are more interesting than most.  A while back, while visiting with a friend of mine that has a shop in San Diego, he showed me about 50-60 Agates that had been polished all around, not just on the front face.  As a rule, I don't buy Agates from Brazil, but I was impressed enough with what he showed me to buy a half dozen of them.  This specimen has an outer band of light- blue with a sandy-yellow colored bands, followed by clear Quartz at the center where there is a cavity lined with a druse of small Quartz crystals.  Not your everyday Agate from Brazil.


Agate & Amethyst geode, Ametista do Sul, Rio Grande do Sul, Brazil
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AD-149  Agate & Amethyst geode  $85

Ametista do Sul, Rio Grande do Sul, Brazil

9.1 x 10.5 x 9.2 cm

A large geode from Brazil's southernmost state. This specimen features finely defined bands of white-off white hue with a center vug filled with euhedral crystals of Amethyst. I acquired this large Agate about 10 or so years ago from a friend who imports a lot of material from Brazil.  I chose it because I had never seen one of this particular color that had an Amethyst vug at its center that had not been made into spheres.


Agate, Steinkaulenberg, Idar-Oberstein, Birkenfeld, Rhineland-Palatinate, Germany
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AD-231  Agate  $35

Steinkaulenberg, Idar-Oberstein, Birkenfeld, Rhineland-Palatinate, Germany

4.4 x 2.3 x 3.5 cm


Here's an example of something that you don't see for sale very often. An Agate from the world's most renowned Agate locality. This specimen has a pleasing and medium-blue hue with a blush of red due to inclusions of Hematite. The specimen on the right features finely banded layers of grey and off-white with a central portion of crystallized Quartz.
The area surrounding the twin cities of Idar & Oberstein gained notoriety for the fantastic Agates & Amethyst lined geodes discovered there in the mid 1500's. By the beginning of the 1800's the production of material had fallen to a small fraction of what was found in its heyday.


Agate, Horní Halže, Klášterec nad Ohrí, Krušné Hory Mountains, Ústí Region, Czech Republic
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AD-150  Agate with Hematite  $75

Horní Halže, Medenec, Chomutov District, Ústí nad Labem Region, Czech Republic

12.3 x 10.4 x 3.5 cm

This Agate is unlike any I have seen from the Czech Republic.  During an early stage of its formation, membrane-like layers of minerals came off the walls of the cavity, broke and were deposited in a colloidal silica solution.  This Agate has a light-blue color that is accented by veins of silver-gray hematite that have colored the Agate red.  A very striking and eye-pleasing combination of colors.


Agate Thunder Egg, Nowy Kosciól, Kaczawskie Mts, Lower Silesia, Poland
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AD-138  Agate & Quartz Thunder Egg  $60

Nowy Kosciól, Kaczawskie Mts, Lower Silesia, Poland

8.5 x 9.3 x 4.1 cm

Here we have a multicolored Agate and Quartz Thunder Egg with a small vug at its center. The Agate portion shows fine banding with an inner rim of flame-colored Chalcedony.  Nowy Kosciól is a classic Polish locality.  Thunder Eggs such as these are highly prized by Polish Agate collectors and are rarely available outside of Europe.


Agate and Quartz, Rimsberg, Birkenfeld, Rhineland-Palatinate, GermanyAgate and Quartz, Rimsberg, Birkenfeld, Rhineland-Palatinate, Germany
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AD-167  Agate with Quartz  $50

Heimbach, Baumholder, Birkenfeld, Rhineland-Palatinate, Germany

8.7 x 4 x 1.7 cm

A deeply-colored agate surrounding a a group of tightly compacted Quartz crystals. In addition to its vivid red color there are swirls of brown which provide a nice contrast of colors. Agates from this locality are very difficult to come by. The area surrounding the twin cities of Idar & Oberstein gained notoriety for the fantastic Agates discovered there in the mid 1500's. By the beginning of the 1800's the production of material had fallen to a small fraction of what was found in its heyday.


Amethyst and Chalcedony geode, Dugway Mountains District, Dugway Range, Tooele County, Utah
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AD-145  Amethyst & Chalcedony geode $50

Dugway Mountains District, Dugway Range, Tooele County, UT

10.1 x 7.3 x 2.6 cm

This is one of the more colorful Dugway geodes that I have come across in my 30+ years of collecting.  What you typically get with a Dugway are washed out earth tones and if you are lucky, light blue Chalcedony and some small crystals of Quartz.  This multi-chambered nodule has a good red-brown hue accented by bands and areas of green with a central chamber of rich-colored Amethyst.  Amethyst is rarely found at this locality.



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AD-202  Barite nodule  $35

Col de Pré Guittard, Arnayon, Drôme, Auvergne-Rhône-Alpes, France

8.5 x 7.1 x 2.5 cm

A Septarian nodule with a core of subhedral crystals of Barite. The Barite has a mild fluorescence. Septarian nodules contain angular cavities or cracks, called “septaria”. This word comes from the Latin word septum, meaning partition.


Agate, Horní Halže, Medenec, Chomutov District, Ústí nad Labem Region, Czech Republic
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AD-235  Agate with Quartz  $25

Horní Halže, Medenec, Chomutov District, Ústí nad Labem Region, Czech Republic

5.7 x 6.4 x 3 cm

A colorful blue and white Agate deep red-colored dendriform inclusions.


Agate, Steinkaulenberg, Idar-Oberstein, Birkenfeld, Rhineland-Palatinate, Germany
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AD-232  Agate  $30

Steinkaulenberg, Idar-Oberstein, Birkenfeld, Rhineland-Palatinate, Germany

4.3 x 4.5 x 3.3 cm

Here's an example of something that you don't see for sale very often; an Agate from the world's most renowned Agate locality. This specimen features finely banded layers of grey and off-white with a central portion of crystallized Quartz. The area surrounding the twin cities of Idar & Oberstein gained notoriety for the fantastic Agates & Amethyst lined geodes discovered there in the mid 1500's. By the beginning of the 1800's the production of material had fallen to a small fraction of what was found in its heyday.



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AD-166  Agate & Quartz Thunderegg  $65

Mount Airy Mine, New Pass District, Lander County, NV

14.2 x 13 x 4.9 cm

Resembling the more famous St. Egidien nodules this specimen features bands of blue-colored agate wrapped around a core of tightly-packed Quartz crystals. This specimen has been polished to a good lustre. Specimens from this remote locality are hard to come by even for us local collectors.


Chalcedony variety Jasper, Cairo, Egypt
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AD-105  Chalcedony  $50

Cairo, Al Qahirah Governorate, Egypt

7.5 x 6 x 2 cm.

When I was in Egypt in April 2010, I saw many nodules of Jasper and Chalcedony just lying around on the ground out in the desert near Cairo.  I wondered why no one has ever offered this material for sale.  In 2011, while at the Tucson show, I was fortunate enough to run into a dealer who had some of these nodules for sale.  I made a trade with him for two of these specimens.  It was explained to me that these colorful nodules are difficult to polish.  Jasper is a dense, opaque, microcrystalline variety of Quartz. Or more strictly; Chalcedony and is usually red, brown or yellow and coloured by Iron oxides.  I think I chose some good ones, with nice earth-colored tones and interesting banding.  One thing that I have noticed in my many years of collecting is that there is not too much available when it comes to Egyptian minerals.  These colorful Chalcedony nodules are sometimes called “Sahara Agate”.



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AD-178  Quartz geode  $85

Juchem Quarry, Niederwörresbach, Herrstein, Birkenfeld, Rhineland-Palatinate, Germany

9.8 x 9 x 9.6 cm

A good-sized, cavernous example of Quartz from the famous Steinbruch Juchem near Idar-Oberstein.  The Quartz crystals on this specimen have good clarity and lustre and are included by Goethite making them appear to be smoky in color. There is a small aperture in the rear of the specimen which helps illuminate this geode's interior. Large examples of this material are not often seen for sale.



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AD-181  Agate Thunderegg  $40

Agate Creek, Etheridge Shire, Queensland, Australia

10 x 6.7 x 2.4 cm

A vividly-colored lithophysae (thunderegg) Agate from Australia. The bands of Agate in this nodule are a deep, red-orange color. I've seen a decent quantity of banded Agates from this locality but thundereggs seem to be much more elusive.



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AD-187  Agate & Quartz Thunderegg  $60

St. Egidien, Glauchau, Zwickau, Saxony, Germany

9.6 x 6.5 x 2.8 cm

This double Thunderegg specimen features bands of deep-red Agate and a core of colorless Quartz crystals in star-shaped formations. St. Egidien is considered to be Germany's premier thunderegg locality.



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AD-191  Agate  $40

Dryhead Agate Mine, Bighorn River Area, Pryor Mountains, Carbon County, MT

6.6 x 6 x .8 cm

A very colorful sedimentary Agate from Montana. Sedimentary Agates are formed in sediments as opposed to being formed by filling cavities in the rock during secondary processes in volcanic rocks. Dryhead" Agates, with their gorgeous colors and patterns locked inside the surrounding nodules, are prized by Agate collectors. This one shows banding of orange-red & ochre encased in a grey-brown-colored matrix. The Dryhead Agates were named after many bison skulls found near the site. That was where the Native Americans were said to run the bisons over the cliff, killing many of them, and then arranging the bison skulls in ceremonial manner.



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AD-192  Celestine & Quartz in Chalcedony geode  $40

Chalcedony Beds, San Rafael District, Emery County, UT

8.8 x 7 x 4.2 cm

A brick-colored nodule of Chalcedony that has a cavity that is lined with colorless Celestine crystals and tiny crystals of Quartz.



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AD-207  Agate (exhibiting displacement)  $50

Estacion Ojo Laguna, Municipio Ahumada, Chihuahua, Mexico

7.6 x 3.8 x 3 cm

A lavender-pink-colored Agate from mexico's most famous agate location. This specimen has an almost transparent body with tight banding in the center. A neat feature of this specimen is a seam running down the left side of the specimen that resulted in the displacement of a portion of the nodule.



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AD-184  Agate & Quartz Thunderegg  $95

Lierbach Valley, Oppenau, Black Forest, Baden-Württemberg, Germany

19.5 x 14 x 6.4 cm

Here we have a very large example of Agate from Germany's Black Forest. The center of this slate-green-colored Agate is filled with Quartz crystals. The two chambers of this Agate have sparkling Quartz crystals and a red-colored mineral, most likely Hematite. There are many Agate localities all over Germany, but few Agates ever make it to the United States.


Agate and Quartz geode, Lierbachtal, Schwarzwald, Germany
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AD-113  Agate and Quartz geode  $75

Lierbachtal, Oppenau, Schwarzwald, Germany

13 x 12 x 3 cm.

Here we have a very large nodule of Agate from Germany's Black Forest.  The center of this slate-colored Agate is filled with Quartz crystals.  The section of this Agate that has the Quartz crystals is outlined by a red-colored mineral, most likely Hematite.  In my 23 years of collecting I have only seen one other example of this material.  There are many Agate localities all over Germany, but few Agates ever make it to the United States.


Agate with Quartz, Idar-oberstein, Germany
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AD-087  Agate with Quartz  $35

Idar-Oberstein, Rhineland-Palatinate, Germany

11.2 x 7.5 x 3.5 cm.

Here's something that you don't see for sale very often. The area surrounding the twin cities of Idar & Oberstein gained notoriety for the fantastic Agates & Amethyst lined geodes discovered there in the mid 1500's. By the beginning of the 1800's the production of material had fallen to a small fraction of what was found in its heyday. This specimen features finely banded gray, white and pink Agate alternating with layers of Quartz. While occasional specimens can be found, there is no steady supply of material from this classic location.


Agate, Idar-Oberstein, Rhineland-Palatinate, Germany
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AD-088  Agate  $30

Idar-Oberstein, Rhineland-Palatinate, Germany

7.2 x 5.4 x 5.6 cm.

Here's something that you don't see for sale very often. The area surrounding the twin cities of Idar & Oberstein gained notoriety for the fantastic Agates & Amethyst lined geodes discovered there in the mid 1500's. By the beginning of the 1800's the production of material had fallen to a small fraction of what was found in its heyday. This polychromatic Agate features finely banded layers of gray, white and pink making for a specimen with a striking contrast of colors. While occasional specimens can be found, there is no steady supply of material from this classic location.