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For the Love of Dendrites

Posted by Stephanie Martin  
Roger Curry September 08, 2012 10:10PM
Rob I have no further information on the gif. I found it on wikipedia commons photo collection while learning about the dendrite formation. I've seen dendrites actually forming; at 32000 ft above the Gibson Desert, and at fumaroles on Vulcano. Excuse me posting the sal ammoniac image again Rob, I know you've seen it before. The first image is ice crystallising from the influx of my breath, due to the slight leak on the window of the jet. This is normal, and is why the hole is there... exhaling into the window and taking photos may not be considered normal.
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Dan Fountain September 09, 2012 01:47AM
I'm not sure what the mineral is. I found these today in a quartz-carbonate vein in the Dead River Shear Zone in Marquette County, Michigan, USA. Associated minerals in the quartz were galena and sphalerite, with minor pyrite and chalcopyrite. The dendrites seem to be "rooted" in what appears to be siderite or ferroan dolomite. Any ideas?
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Erik Vercammen September 09, 2012 09:50AM
This thread is nearly a "Best of" article: just an introduction, with the headlines of another thread about the compostion of Mn-dendrites, and a warning not to confond dendrites with fossils!
Ian Jones September 09, 2012 12:09PM
Let's not forget dendritic gold http://www.mindat.org/photo-5688.html, this one from Devon:-)
Stephanie Martin September 12, 2012 05:56AM
Roger - great entertainment, thank you for those high altitude dendrites and a somewhat shroud-like impression! And those fumarole feathers are sweet and delicate. I wanted to make the gif my avatar, but alas it was slightly too large and I couldn't resize it without losing the animation. I'll work on that.

Dan - Those are really wonderful pieces. It would be hard to know which oxide they are without analysis. Both manganese and iron oxides can form dendrites and both be present. You can't always go by colour because some of the managanese oxides can be brown and likely some of the iron oxides could be black.

Ian, thanks for filling the gap and adding a nice dendritic gold specimen. They sure look much like feathers as the sal ammoniac above. The dendritic form is no accident. It appears in many places, not just trees and plants, but also neurons, rivers and as just mentioned, feathers to name a few.

Here are some cabachons with brownish dendrites in agate from Uttar Pradesh, India. When I have time I will add the sizes and perhaps photoshop the background to black to highlight them better.

Edited 3 time(s). Last edit at 09/13/2012 02:17AM by Stephanie Martin.
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Stephanie Martin September 12, 2012 06:02AM
More agate cabachons from India,

You can see some brownish "clouds" around some of the dendrite groups.

This is moss agate, while not technically an oxide, it does mimic the dendritic form. These are likely chlorite group inclusions.

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Stephanie Martin September 12, 2012 06:12PM
Big thanks to Dan for helping to get my avatar on board! And big thanks to Rog for originally posting it!

stephanie :-)
Bradley Plotkin September 12, 2012 11:20PM
Here is a dendrite from New Jersey. Snake Hill Quarry, Secaucus New Jersey - Brad.
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Rick Dalrymple September 13, 2012 02:10AM
I never realized how fascinating dendrites could be. This is one of the best threads ever.

Thanks Stephanie:-D
Stephanie Martin September 13, 2012 04:28AM
Thanks Rick, glad you are enjoying it. A thread is only as good as the contributors make it, so thanks so much to you and everyone for your numerous contributions and enthusiasm. :-) That is a pretty high expectation to be one of the best, but we shall try! I was just hoping to share a bit of fun with everyone and learn something in the process.

In addition to the brown tones you often see dendrites that "bleed blue". This is very typical of the medicine bow agate that I have seen. The secondary colour of course depends on which manganese oxide is to blame.

Medicine Bow agate, Wyoming.

Parral Agate, Mexico
Wave or ripple patterns are noted in this agate.

These dendritic talc slabs from Montana remind me much of "Delft Blue" china. Very distinctive.

Edited 1 time(s). Last edit at 09/13/2012 04:38AM by Stephanie Martin.
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William W. Besse September 16, 2012 08:15PM
Thought I would share a slab I saw (unknown composition and locality) that is about 20cm by 40cm.

Actually there are several I saw...

And even MORE...

For those of you that go to the Tucson show you might recognize this as a dealer's warehouse on Main just north of Speedway.

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Rick Dalrymple September 19, 2012 09:46PM
This is a local material. It is often dark red with black dendrites on the outside and then yellow with dendrites on the inside.

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple September 22, 2012 03:01AM
A couple of more dendrites in agate...

I know I am in my own little world, but everyone knows me here.
Stephanie Martin September 22, 2012 07:07PM
Bill, thanks for pics from Tucson. I have seen that photo before and until I saw the close up did not realize those tiles were full of dendrites! Gives a whole new meaning to the term "climbing the wall" lol.

Rick, thanks for your latest pics too. The yellow material reminds me of the opalite from Australia.

This week I received a little unexpected bonus. I have a few of these calcites from Ahmednagar, Maharashtra, India, but this one came with a little stow away dendrite inside the longest crystal. None of my other similar calcites from there have any, this particular specimen seems to have a good amount of stubborn matrix attached that appears to be a mix of quartz grains and clay, likely the source for the dendrite. It's not an amazing example but it is very interesting to me coming from this area, I have not seen dendrites on or in any specimens from Maharashtra, an area typically known for zeolites.

Here's the little surprise I found:

whole specimen is approximately 8.x 5.5 cm

I'll be posting more stuff as manage to get the photos done.
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Rick Dalrymple September 23, 2012 04:18AM
That is a great find.

Here are a couple of more chalcedony specimens with dendrites.

More to come.

I know I am in my own little world, but everyone knows me here.
AM Mizunaka September 23, 2012 06:25AM
Another bonus dendrite hiding on a mimetite specimen from Mexico. The original piece is 7.4 x 4.2 cm. The dendrite section is around 6 mm wide.

Stephanie Martin September 25, 2012 05:15AM
AM, you always come through with a great contribution! That is a stunning combo. Thanks for sharing that one. I'll be checking my mimetites more thoroughly!

In general I've been noticing a lot more bonus dendrites and it can only add to the appeal of the specimen. For example, this material is not the most photogenic, but it is made more interesting by the additional "artwork".

There are dendrites dotted all over the piece, not uncommon for the material and the clay environs, but despite being small this one caught my eye because it seems to have a shadow or a negative mirror image, perhaps a new dendrite forming.

"Me and my shadow".
Dendrites on palygorskite, also known as mountain leather
Velké Hydčice, West Bohemia, Czech Republic
dendrite approx 4mm

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Stephanie Martin September 27, 2012 04:20AM
At the Scarborough, Ontario show we came across this strange material: dendritic lead.

The fellow selling them said he "grew" them by dissolving lead in nitric acid and then with the magic of electricity created these forms. So I just had to have them :-D That reminds me, lightning and their by-product fulgurites are also of the dendritic persuasion. I'll have to try and rustle up some good examples of those yet too.

approx 15 mm length

small approx 5mm, larger approx 10mm
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Timothy Greenland September 27, 2012 08:47AM
Dear Stephanie,

Thank you for starting this!

Here are some shots of paving slabs around my Brother-in-law's garden in the Drôme department of France. I suspect they are of fairly local origin, but can't guarantee that... The black ones are probably manganese oxides and the co-existing ones probably iron. The jointing between slabs is approx 1 inch wide on the average...

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Timothy Greenland September 27, 2012 08:49AM
And just a last one for luck...


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Roger Curry September 27, 2012 10:05AM
I'm glad you posted some artificial dendrites Stephanie, here's a couple...

Electrically grown snowflake. (This has been on my hard-drive for donkeys. Could be copyrighted, I'll attempt to find out where I got it and gain permission or removal) (edit - courtesy of Kenneth G. Libbrecht, www.snowcrystals.com - well worth a visit! Thanks for the URL Cliff)

Artificial fulgurite production youtube

There appears to be two types of dendrite formation, the ordered crystalline type (ice, ammonium chloride etc.) and the chaotic fractal type (manganese oxides, lead etc). However, this I think is only a scale effect, i.e. if a snowflake continued to grow indefinitely, defects would lead to distortions from perfection, until chaos theory would predict an unorganised large scale form such as is shown by manganese dendrites (2D) or flos ferri & fulgurites (3D). Only a guess...


Edited 1 time(s). Last edit at 09/27/2012 07:41PM by Roger Curry.
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Dennis Tryon September 27, 2012 03:18PM
Another dendritic Agate slab from Mexico

Stephanie Martin September 27, 2012 10:12PM
Thanks guys for the posts!

Rog, since you started with a link to the lab created fulgurites, here are some youtube links you might find interesting (if you haven't already seen them) regarding the creation of Lichtenberg figures aka "Captured Lighting" and "Shockfossils". If you needed an idea for a gift paperweight for the exec who has everything, these are rather artful.

The first one is a few minutes long, the second one is about 9 minutes.
After you watch the first one, you can click on the link below it to the shockfossils gallery to see some cool images.



steph :-)

Edited 1 time(s). Last edit at 09/27/2012 10:18PM by Stephanie Martin.
Rick Dalrymple September 30, 2012 05:25AM
Here is a fluorapatite with three dimensional dendrites. Click on the image to see the child image showing the base with the wholes of the dendrites. They are about 1-3mm in diameter. I have never seen any other dendrites similar to this.

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple September 30, 2012 05:30AM
Here are some cinnabar dendrites in agate from Nevada. This photo is of a cabochon in a pendant.

I know I am in my own little world, but everyone knows me here.
Stephanie Martin October 01, 2012 03:07AM
Rick, thanks for those. It's always nice to see the cinnabar variety as they are colourful.

As for the 3D dendrites, I actually have something akin to yours, only the samples I have are in calcite. I was reluctant to post them as the precise locality was not confirmed. The locality information supplied was Ougoud, Morocco, but there is no such match. The closest I could find on google was Tishremt N'Ougoud, in Er Rachidia Province. There are similar sounding towns and I always wonder about translation and the often ambiguous info provided to conceal finds, but with the given information this seems to be the best match possible. It is south east of Goulmina. It is rather timely to post this as the conference for Morocco is coming up soon. Perhaps people will be more on the look out for dendrites in their field trips.

There are 2 samples that appear to have been part of the same geode (?) although the pieces don't match together like puzzle pieces. The dendrites wrap around the pieces like a garland. I wonder if there is any connection to all those quartz geodes with goethite needles?

You can see the 3D impressions in the close up 3rd photo.

4.5 x 3.5 x 3.5 cm and 5.5 x 5 x 3 cm

Edited 1 time(s). Last edit at 10/01/2012 03:28AM by Stephanie Martin.
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Stephanie Martin October 01, 2012 03:10AM
Here is the larger piece:

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Don Windeler October 01, 2012 07:43AM
Stephanie, those Moroccan pieces are way cool, especially the larger one in the second set of photos. Really nice.

I haven't been taking many photos of late, so I'll have to be content with recycling a shot from my gallery. There are lots of dendritic coppers out there, but this is one of my favorite examples from the collection: a 10.6cm long crystallized piece from the Adventure Mine, Ontonagon County, Michigan.

This piece is flat and looks to have grown in a seam, but whatever it dendritically wormed through is now long gone!

Stephanie Martin October 03, 2012 03:27AM
Don, that's a tall beauty!!!

From copper to a copper mineral, this piece exhibits a row of dendrites sprouting up between the layers. There are also hints and spurts of them between other bands throughout the sample. They do look "3D" but I was thinking that it is perhaps just the luck of the way the piece cleaved naturally Normally they are buffed out and polished removing any traces of depth, so I guess you have to catch them before they get smoothed over otherwise you wouldn't know. I didn't need another piece of malachite but couldn't resist the dendrites on the green canvas.

Malachite with dendrites (probably Congo)
overall size 4 x 2.5 cm approx

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Rick Dalrymple October 05, 2012 05:11AM
Another dendritic copper from the Bingham Copper Mine...

Rick Dalrymple October 05, 2012 05:17AM
Another one from Bingham, turquoise with dendrites on it. I don't think they are in the turquoise, just on it.

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple October 05, 2012 05:29AM
And a silver from Germany...

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple October 05, 2012 05:41AM
I know coppers have been done here but I really like this one from Namibia,,,

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple October 05, 2012 11:53PM
Stefanie, I like those 3D dendrites. I see similar ones in a similar rock here every once-in-a-while:-)

This stuff is listed on mindat as jasper from china but it is not a jasper. The slab is so soft that it actually has warped from sitting on a stand. It is now slightly bowed in the center. I would say it is a very soft siltstone or claystone.

I do like the tree-like dendrites.

I know I am in my own little world, but everyone knows me here.
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Stephanie Martin October 12, 2012 05:56AM
As I was mentioning above regarding buffing the dendrites for lapidary items, this can be seen in the egg below. The longer dendrites show areas that were not completely buffed out. Sorry about the white spot light refflections...

From Peru
Dendrites, calcite

Some cabachons also from Peru, material is known as Machu Picchu Stone and contains calcite, quartz and the darker red areas are indicated as being caused by the presence of cuprite.

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Stephanie Martin October 12, 2012 06:03AM
More from Peru, these are dendritic pink opal carvings

A matched pair of bluish dendritic "landscape" opals

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Stephanie Martin October 12, 2012 06:05AM
another carving, this one is Tanzanian opal

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daniele ramoino October 13, 2012 03:29PM
hi everyone,

Thanks to Stephanie and Roger, i just found to have a rock with dendrites,

it come from Maroc desert

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James Pool October 13, 2012 05:01PM
Here's a closeup of what is likely dendritic silver in an unpolished slab of sowbelly agate from Creede, Colorado. Much of the silver ore from there occurs in banded amethyst seams that an early miner called sowbelly agate due to the bacon like appearance of some slabs although in a different color. The specific mine for this slab is unknown but it may be from the Commodore.

There is a very 3d appearance for the dendrites when the slab is wet in water. The largest dendrite is about 1/4 inch or so.
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Rick Dalrymple October 26, 2012 03:51AM
I thought I would revive this thread. I am sure there are many more dendrites out there.

This is a front and back of the same slab. I just can't decide which is the front and which is the back:-)

It is from a Priday Thunderegg I collected about 12 years ago.

I know I am in my own little world, but everyone knows me here.
Stephanie Martin October 28, 2012 05:51AM
Thanks Rick... I have much more to post, just getting things photographed is a challenge...

Roger mentioned flos ferri on the previous page, and I have always found these funderful. Here are a couple, and Gail has posted a lovely blue one on the favourites thread if you care to have a peek at that (page 27). I have a little green one but it doesn't have many branches to show the form well.

Aragonite var flos ferri (unforunately some branches were damaged in transport)
Příbram, Central Bohemia Region, Bohemia (Böhmen; Boehmen), Czech Republic
approx 30 x 20 x 20 mm

Aragonite var flos ferri
Bisbee, Arizona, USA
approx 6 x 6 x 5 cm

In addition, cracks and crack formation also fall into dendrite territory. Below is a septarian concretion from Morocco that shows such crack formation that has been filled in by calcite. This is much different than the lovely dendritic concretion section shown by Daniele on the previous page also from Morocco. I hope Daniele finds more of that material to post, it is quite amazing.

Calcite, sedimentary/septarian nodule
Oujda, Morocco
9.5 x 7 cm

Edited 1 time(s). Last edit at 10/29/2012 12:01AM by Stephanie Martin.
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Dan Fountain October 30, 2012 03:21PM
I was out digging for pyrolusite a while back and this was the first piece of rock I split out. My previous "best" dendrites flank it.
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Matt Ciranni October 31, 2012 04:19AM
Does this count? Picked this up in the Marsing/Homedale area (near the Idaho/Oregon border) last summer. It's some type of dendritic agate that is commonly found in that area. Some local jewelers apparently gather and cut slabs of this material, and create pendants out of it.
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Stephanie Martin October 31, 2012 06:02AM
Dan, I just have one word: W.O.W! (picks jaw off floor)...

Stephanie Martin October 31, 2012 06:04AM
Hi Matt,

Thanks for posting. Yes, there is at least one dendrite that I can confirm about half way down on the far right of the specimen, the other dark spots are hard to tell if they are just dirt or a coating of some type, but there could be more dendrites hiding in there.. Mostly these look like quartz stalactites which also do follow dendritic form. Oregon does have some lovely material to contribute!

stephanie :-)
Rick Dalrymple October 31, 2012 01:25PM
I knew there were more great dendrites out there(tu)

Stephanie, I don't get how a septarian is a form of a dendrite?
I do love the flos ferri though:-)
Rick Dalrymple October 31, 2012 01:33PM
Here is a blue aragonite from a mine only 20 minutes from my home...The Tintic Standard Mine, Eureka, Utah

and one from a mine right around the corner from the...The Baltimore Tunnel, Mercur, Utah

Stephanie Martin October 31, 2012 05:03PM
Those are beautiful Rick!

Regarding the septarian, it is not the actual concretion, but rather the crack formations from the weathering process and those have been filled by calcite in the nodule. Cracks are not actually dendrites themselves, however their formations are subject to the same fractal chaos and therefore can be lumped generally under the dendrite umbrella. Hope that helps.

stephanie :-)
Rick Dalrymple October 31, 2012 06:48PM
Thanks Stephanie,

I think we have a difference in semantics. The internal structure is not a weathering process. It is caused by the internal collapse of the hollow cavity. The hollow cavity is thought to be created when a biological mass, like algae, decay away. Many of the solid ones have other nucleus such as ammonites or other shells. I even have one that I am sure is an algal ball that resembles dinosaur bone. There is a lot of research done on these from Utah. The ones from Morocco have the same genesis. BTW: I have collected the ones here in Utah many times. It is a great field trip and if you are ever in the area, I would be glad to show you around.

As for the fractal pattern (not really chaos as fractals are not random), I couldn't agree more. They are wonderful and that thought adds a whole new dimension to this thread. I am now looking forward to adding a whole new batch of images:-)

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple November 03, 2012 06:00AM
Here are a couple of polished agate cabs. My son Zeke did the cutting and polishing.

I know I am in my own little world, but everyone knows me here.
Rick Dalrymple November 03, 2012 06:01AM

I know I am in my own little world, but everyone knows me here.
Rock Currier November 03, 2012 10:19AM
Rick, that a really beautiful dendrite and cab. I see you have uploaded it to our gallery. Thank you for that. Do you know which Oregon locality it is from?

Rock Currier
Crystals not pistols.
Philip Bluemner November 03, 2012 12:34PM
I love dendrites since being a little one. It's so fascinating and fun following the branching growth.
Here's a dendritic fluorite from Moepe Mine, South Africa


Best regards
Glenn Rhein November 03, 2012 03:58PM
Wow Rick, that blue Aragonite is cool stuff

About 2-3/4 inches , Most of the Meionite here in Amity has this dendrite coating but this is one of the darker pieces.
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Rick Dalrymple November 03, 2012 10:41PM
Rock, Thanks. I got the slab in a collection and it was labeled with pencil " dentrite--Oregon", unfortunately:-( I really wish there had been more.

Glen, Thanks. I love that piece too. My friend collected that about 20 years ago when there was lots in the mine. Now it has been reclaimed:-(
Rick Dalrymple November 04, 2012 02:07AM
Here is the septarian I mentioned earlier, with the algal ball in the center. It is from Muddy Creek and was collected last year by a friend.

Rick Dalrymple November 04, 2012 02:21AM
Chrysoprase with dendrites.

Rick Dalrymple November 04, 2012 02:28AM
This material is often sold as jasper but it is really a siltstone. The dendrites are considered stromatolite, though I don't know that they have been studied.

Glenn Rhein November 04, 2012 03:11AM
Rick Dalrymple Wrote:
> Glen, Thanks. I love that piece too. My friend
> collected that about 20 years ago when there was
> lots in the mine. Now it has been reclaimed:-(

Hey Rick, No mine here in Amity NY just the backyard and some woods. What mine are you refering to ?
Rick Dalrymple November 04, 2012 03:54AM
It is from the Tintic Standard Mine (Tintic Standard Mines 2 & 3), East Tintic District, East Tintic Mts, Utah Co., Utah, USA.

It is about 30 minutes from my house. Unfortunately, it has been reclamated recently.

I know I am in my own little world, but everyone knows me here.
Stephanie Martin November 05, 2012 05:43AM
Rick, thanks for the notes regarding the Utah septarians. I have no argument regarding the formation of the concretion around a nucleus or the subsequent internal collapse. My wording was perhaps over simplistic in an attempt not to get into too long a discourse. From my understanding of their formation these concretions were subject to different geologic processes, including weathering when the seas dried, during their longterm formation (or lack thereof of weathering in an arid climate after the seas dried from their original birth in water). Then followed by subsequent rehydration and solution resulting in calcite filling. And regarding fractal and chaos, again this was over simplistic, as I was referring to stochastic processes in 3 dimensions. So as you said, it is semantics :-)

I have a bit of catching up to do so I better get cracking (pun intended)...:-D


Edited 1 time(s). Last edit at 11/05/2012 06:20AM by Stephanie Martin.
Stephanie Martin November 05, 2012 06:07AM
Thanks to all for continued interest and posting awesome specimens!

Rick, that cab IS your own little world... it's cabtastic. Kudos to your son for doing such an outstanding job orienting the stone to full potential.

James - thanks for posting that silver, I will definitely have to look at my sowbelly agate a little closer!

Philip, that is really cool fluorite from an unusual location. That's what I like to see :-D

Glenn, you know I love those! Were you ever able to determine if the dendrites were alanite? In any case that's another lovely specimen.

Getting back to dendrites...

from Kazakhstan

dendritic opal rough
4.5 x 4 x 3 cm approx

agate cabachons
42 x 21 mm and 45 x 17 mm approx
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António Joaquim Monteiro November 05, 2012 08:58AM
Dendrites from Serra da Mina mine, Cercal.
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Alex Homenuke November 07, 2012 12:21AM
I've been meaning to photograph this and post it since this thread began. I don't know how you all find the time to do this :)-D

Descloizite dendrites in dolomite(?) surrouded by botryoidal smithsonite, 10cm, Berg Aukas

Edited 1 time(s). Last edit at 11/07/2012 12:22AM by Alex Homenuke.
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Stephanie Martin November 09, 2012 07:54AM
Antonio and Alex, very intriguing samples!

Antonio - the white dendrites are very unusual and very contrastive, I am curious what mineral they are.
Alex - I don't think I have ever seen descloizite dendrites! Amazing specimen. Glad you found the time to share that treasure.

Here's one from my weird file - a drilled agate pendant, but it has an odd formation of a completely encased bubble inside the agate that has a globular type dendrite forming in it. Unfortunately the agate is too thick and a bit milky so it doesn't allow for a clear focus on the blob, so it will always remain fuzzy, but there is no mistaking it's silhouette. "The Mushroom". The supplier tried to get more information for me on the origin of the material, however the only available information was that the agate location was from China. I am not convinced, but that's all that I could find out. I suspsect it could really be from Indonesia or possibly India. Approx 32 x 22 mm overall.

Edited 1 time(s). Last edit at 11/09/2012 07:56AM by Stephanie Martin.
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Rui Nunes November 09, 2012 11:58AM
Dear Stephanie,
Regarding Antonio's dendrites: I have something similar from this mine but not so pretty. I think it's "sugared" barite in a mn oxides environment.
Best wishes

Edited 1 time(s). Last edit at 11/09/2012 12:07PM by Rui P Nunes.
Dan Costian November 09, 2012 08:47PM
I've never seen red dendrites (hematite I guess) within a crystal of yellow apatite (Cerro del Mercado Mine, Mexico).

Edited 1 time(s). Last edit at 11/12/2012 03:14AM by Dan Costian.
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Dan Costian November 09, 2012 11:32PM
These dendrites on quartz are from Wyoming. They are crystals, with metallic luster, looking like sulfides.
Can anybody tell me what can they be? They look like manganese oxide but probably are not.

Edited 1 time(s). Last edit at 11/12/2012 03:11AM by Dan Costian.
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Rick Dalrymple November 17, 2012 04:12AM
I don't know what those dendrites are but they are cool(tu) Why don't you think they are manganese oxides?

Here are some more I came across...

The first one is white dendrite-like feathering in an Oco agate geode. These are common but still beautiful.
open | download - 2012-11-16 16.53.46.jpg (223.7 KB)
Rick Dalrymple November 17, 2012 04:16AM
This two are manganese oxides in what is commonly called Tiffany Stone.. It is the beryllium ore "bertrandite" colored with fluorite and manganese oxides. It is mined near Topaz Mountain, Juab County, Utah
open | download - 2012-11-16 16.52.50.jpg (266.9 KB)
open | download - 2012-11-16 16.53.02.jpg (252.6 KB)
Rick Dalrymple November 17, 2012 04:31AM
This is one of my favorite. It resembles a fire work or maybe a dandylion, or maybe a signal flare...

Rick Dalrymple November 17, 2012 04:42AM
This is an unusual one. It is dendrites of hessite in quartz. There is some minor gold mixed in. It looks more dendritic in person.

Rick Dalrymple November 17, 2012 05:03AM
Here are some beads with dendrites.

One is green chrysoprase with dendrites from Australia and the other is dendritic opal but I don't know where it is from.
open | download - 2012-11-16 16.51.47.jpg (139.1 KB)
open | download - 2012-11-16 16.51.26.jpg (332.1 KB)
Rick Dalrymple November 19, 2012 04:26AM
Here is a dendrite in malachite. I don't know if it is a manganese oxide or something else.

I know I am in my own little world, but everyone knows me here.
open | download - malachite close-up dendrite.jpg (55.3 KB)
Rick Dalrymple November 19, 2012 04:27AM
Oh yea, the field of view is about 4cm.
Rick Dalrymple November 19, 2012 04:39AM
Here is a polka dot agate slab from Oregon
Stephanie Martin November 19, 2012 06:02AM
Dan, those are remarkable and intriguing specimens! The apatite is really drool worthy and I am also curious to know what those metallic dendrites might be in your other piece. There has always been speculation that metallic dendrites are pyrolusite, however that has not yet been reported with analysis. I will try to see if I can find any references from that area that might indicate any probable ID.

Rick, thanks so much for your dedication. Great pieces, I really love the "dandelion" or however you choose to name it. The Hessite was a nice touch also.

I am still having a bit of fun with agates, these come from the same lot as the "Mushroom" above. There seems to be a number of them that suggest images, at least in my overactive imagination.

rose and thorns

celestial body rising on horizon

crooked ghostly smile
open | download - P1410201(1)(1).jpg (350.5 KB)
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Alex Homenuke November 19, 2012 04:32PM
Or is it a moustache for "Movember"??
John A. Jaszczak November 19, 2012 07:25PM

Interesting that the dendrites seem mostly to have simple chemistries. Here is a lovely stellate dendrite of graphite on graphite from the Gouverneur Talc Company mine #4, Harrisville, Lewis Co., New York.
open | download - 345-05micronbar-med.jpg (767.7 KB)
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