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Gallery 10  Agates, Geodes & Thundereggs

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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 most 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.


Opal nodule, Yowah Opal Field, Paroo Shire, Queensland, Australia
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AD-146  Opal nodule  $35

Yowah Opal Field, Paroo Shire, Queensland, Australia

6.9 x 3.6 x 1.7 cm

This striking specimen of “Yowah Nut” Opal consists of a Sandstone nodule that is permeated by Opal of many different colors that it makes for a very colorful and aesthetic specimen.  This is the first one of these that I have encountered that has a hollow center.


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.


Opal variety Geyserite, Yellowstone National Park, WY
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AD-142  Opal variety Geyserite  SOLD
(collected in 1877)

Yellowstone National Park, WY

2.5 x 2 x 2 cm

So-called "Geyserite" is a variety of Opal that is formed in fumarole deposits. This specimen was collected by a Dr. Joseph Leidy in 1877 on a trip to what is now Yellowstone National Park and brought back to give to the Academy for its collections. Dr. Leidy returned with a half a dozen samples all with the same number hand painted on the backsides, denoting their common origin. This piece comes with a copy of the original label. Collecting in the park is prohibited making this old-timer a true American treasure.


Malachite geode, Mashamba West Mine, Kolwezi District, Katanga, Democratic Republic of the Congo
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AD-139  Malachite geode  $95

Mashamba West Mine, Kolwezi District, Katanga, Democratic Republic of the Congo

4.5 x 3.9 x 3.6 cm

Despite its size, this Malachite geode really has a presence.  The vug of this specimen shimmers very much like velvet due to the dense sheaves of micro-acicular crystals. This specimen is solid Malachite with a small crystal of Barite protruding from the edge of the specimen's vug.  Specimens such as these are quite uncommon despite the fact that there is so much Congolese Malachite available to collectors.


Barite & Calcite geode, Muddy Creek, Orderville, Kane County, Utah
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AD-136  Barite & Calcite geode  SOLD

Muddy Creek, Orderville, Kane County, UT

10.8 x 9.6 x 4.8 cm.

Over the years we have seen tons of Calcite Septarian specimens from Orderville, Utah offered for sale as spheres, bookends, carvings, etc...  Seen less often are traditional nodules.  Of all the Septarian nodules found in Utah; the rarest & most sought after are the specimens that contain Barite.  When material from this location was abundant you could go to any big mineral show & you would see thousands of Calcite Septarian specimens. You would indeed be fortunate to find one containing Barite.  And even more fortuitous would be to find one of this quality.  Another thing this fine specimen has going for it is the fact that it fluoresces a vibrant yellow.


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.


Amethyst & Calcite, Juchem Quarry, Niederwörresbach, Herrstein, Hunsrück, Rhineland-Palatinate, Germany
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AD-134  Amethyst & Calcite geode  SOLD

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

6.7 x 5.4 x 4.8 cm.

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 a Hematite coated crystal of honey-colored Calcite almost completely filling an Amethyst geode.


Agate & Quartz geode, Valle Escondido, San Rafael Department, Mendoza, Argentina
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AD-148  Agate & Quartz geode  $35

Valle Escondido, San Rafael Department, Mendoza, Argentina

5 x 4.6 x 3.8 cm

A very colorful specimen from south America's other agate location, Mendoza Argentina.  Agates from this location have a reputation for being as colorful as their Brazilian counterparts.


Agate & Amethyst geode, Ametista do Sul, Rio Grande do Sul, Brazil
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AD-149  Agate & Amethyst geode  $65

Ametista do Sul, Rio Grande do Sul, Brazil

9.1 x 10.5 x 9.2 cm

I acquired this 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.  and I have yet to see another like it.  It was only recently that it dawned on me that I had seen this material, but it had been made into spheres. Which explains why I had only seen this one intact geode half.


Calcite geode, US Highway 27 Roadcut, McCreary County, KY
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AD-135  Calcite Geode  $60

US Highway 27 Roadcut, McCreary County, KY

11.5 x 9.5 x 5.2 cm.

A really cool specimen. Although it is not apparent in the photo this specimen is very 3 dimensional. Also, the stacked brownish rhombs of Calcite make for a nice contrast against the lining of smaller white Calcites.


Opal nodule, Spencer Opal Mine, Spencer, Clark County, Idaho
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AD-143  Opal nodule  $350

Spencer Opal Mine, Spencer, Clark County, ID

8.4 x 7.7 x 6.1 cm

When you think of American Opal, the Virgin Valley in Nevada is usually the first to come to mind.  This specimen hails from America's other large Opal location, Spencer, Idaho.  With a population of 38, it is home to one of the largest Opal deposits in the United States.  This is one of the most vividly colored Opals of this size that I've seen from this location.  While the center of this nodule is opaque, the rest of the specimen more than makes up for this.  This colorful Opal nodule has a strong saturation of color, more than my photographic skills can capture.  Broad flashes of green, blue, violet and a little red can be seen no matter how the nodule is oriented.  The Opal at this mine are contained in a Rhyolite and Obsidian flow with abundant gas pockets. Hydrothermal fluids from hot spring activity filled the pockets with both common and precious Opal.  A colorful specimen that is sure to brighten up any mineral display.


Agate Thunder Egg, Nowy Kosciól, Kaczawskie Mts, Lower Silesia, Poland
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AD-137  Agate Thunder Egg  $60

Nowy Kosciól, Kaczawskie Mts, Lower Silesia, Poland

10.2 x 9.2 x 4.4 cm.

A multicolored Thunder Egg type Agate with a hollow center from a classic Polish locality.  Thundereggs such as these are highly prized by Polish collectors and are rarely available outside of Europe.


Agate with Quartz, Sweet Home, Linn County, Oregon
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AD-131  Agate with Quartz  $75

Sweet Home, Linn County, Oregon

10 x 7.3 x 4.6 cm.

A beautiful translucent nodule of Agate. The vug in the center is lined with lemon-yellow-colored Quartz crystals.  I backlit this specimen a little to better illustrate its translucency.


Pyrite in clay nodule, Ulyanovsk, Povolzhsky Region, Russia
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AD-132  Pyrite in clay nodule  $60

Ulyanovsk, Ulyanovsk Oblast', Povolzhsky Region, Russia

7.5 cm. x 8.5 cm. x 5 cm.


These iridescent Pyrite nodules were quite popular during the short time that they were available in the mid 1990's. Put one of these in your mineral cabinet and it will add a lot of sparkle to your collection. This specimen is nearly a complete half-section. Almost all of these that were offered were not hemispherical in shape, but rather were just chunks of clay with pyrite on them. I think that this can be attributed to the fact that the internal fracturing and the hardness of the nodule were not conducive to splitting them cleanly in half.


Calcite Geode, Bou Azzer District, Tazenakht, Ouarzazate Province, Drâa-Tafilalet Region, Morocco
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AD-147  Calcite geode  $35

Bou Azzer District, Tazenakht, Ouarzazate Province, Drâa-Tafilalet Region, Morocco

9.5 x 4.7 x 7.2 cm

A geode filled with many lustrous and clear crystals of Calcite measuring up to 1.7 centimeters in size.  If you examined, in person, the matrix that these occur in you'd be surprised that they can be extracted more or less intact.


Calcite Geode, St. Francisville, Clark County, Missouri
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AD-072  Calcite Geode  $50

St. Francisville, Clark County, Missouri

9 x 6 x 4 cm.

A showy specimen of translucent and lustrous Calcite crystals inside of a Quartz-lined Geode.  This specimen is from an obscure location and is older material that is not often seen for sale.


Chalcedony, Agate and Quartz, Potato Patch, Imperial County, CA
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AD-126  Chalcedony, Agate and Quartz  $50

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.  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.


Agate, Juchem Quarry, Niederwörresbach, Herrstein, Hunsrück, Rhineland-Palatinate, Germany
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AD-133  Agate  $35

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

6.5 x 3.4 x 2 cm.

The region surrounding Idar-Oberstein has been a source of colorful and interesting Agates for nearly 500 years.  This interesting example features a light coffee-creamy colored Agate with a red area near the center of the vug.  You don't seem to see many examples of German Agates for sale here in the United States.


Agate with Amethyst, Idar-Oberstein, Rhineland-Palatinate, Germany
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AD-089  Agate with Amethyst  $60

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

8.2 x 7.1 x 3.7 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 culminating with a vug of tiny Amethyst crystals in its center.  While occasional specimens can be found, there is no steady supply of material from this classic location.


Opal Thunder Egg, Opal Butte, Morrow County, OR
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AD-141  Opal Thunder Egg  $30

Opal Butte, Morrow County, OR

5.5 x 4.7 x 2.4 cm

One thing that Oregon has an abundance of is Thunder Eggs.  There are plenty of Thunder Eggs that are filled with Quartz and Agate, but not many that are filled with Opal.  This specimen has very subtle pink-colored flash.


Agate Thunder Egg, Heiterer Blick, Kuhschnappel, Germany
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AD-111  Agate Thunder Egg  $30

Heiterer Blick, Kuhschnappel, Saxony, Germany

6.7 x 5.3 x 1.8 cm.

Here we have a section of a Honey-colored Agate Thunderegg included by an unknown green mineral.  There are many Agate localities all over Germany, but few Agates ever make it to the United States.


Agate and Quartz, Thunder Egg, Zwickau, Saxony, Germany
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AD-112  Agate and Quartz Thunder Egg  $25

Zwickau, Saxony, Germany

6.4 x 6 x 3 cm.

The center of this Agate is filled with blue and white Chalcedony and is underscored by a string of coarsely formed Quartz crystals.  This Agate is from the Type Locality for the mineral Celadonite, but I can not say for sure whether or not the green mineral in this specimen is Celadonite.  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 section 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.


Aqate and Quartz geode, Iraí, Alto Uruguai Region, Rio Grande do Sul, Brazil
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AD-118  Agate and Quartz geode  $25

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.


Quartz with Calcite and Hematite, Potato Stone, Dulcote Quarry, Somerst, England, UK
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AD-104  Quartz, Hematite & Calcite nodule  $125

Dulcote Quarry, Wells, Somerset, England

13.5 x 11.7 x 7.6 cm.

Often referred to as “Potato Stones” by the local collectors because the outer portion of these nodules resemble a potato.  Although there are many of these to be found in the hills & surrounding valleys, these once abundant geodes and 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.


Dolomite and Quartz Geode, Warsaw, Hancock County, Illinois
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AD-101  Dolomite and Quartz geode  SOLD

Warsaw, Hancock County, IL

7 x 5.3 x 4.6 cm.

One of the more obscure geode locations in the midwest is Warsaw, Illinois which is a little bit south of and just across the border from the more famous, classic locality, Keokuk, Iowa.  The Warsaw geode areas have yielded some pretty good specimens over the years.  This specimen that I am offering here is one of the best looking Dolomite geodes that I have seen from this locality.  This specimen consists of a shell of Calcite with a layer of tiny, clear and sparkly, Quartz crystals which serve as a host for numerous, curved, Dolomite crystals.  A top-notch specimen from America's mid-west.


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.


Agate and Quartz Thunder Egg, St. Egidien, Glauchau, Saxony, Germany
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AD-090  Agate & Quartz Thunder Egg  $65

Saint Egidien, Glauchau, Saxony, Germany

10.1 x 7.8 x 4 cm.

The tortured form of the inner space of this nodule is evidently due to pressure from inside as it formed.  This specimen features a band of red Agate and a core of colorless Quartz.  This colorful specimen is from the very famous and classic German locality, Saint Egidien. Agates and Geodes from Germany are treasured by European collectors and are not easy to come by.