Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery
bannerbannerbannerbannerbannerbanner

For the Love of Dendrites

Posted by Stephanie Martin  
avatar
Dean Allum November 23, 2012 10:24PM
I ran across this link regarding the chemistry of dendrites. Perhaps it is appropriate for this thread:
Caltech:manganese dendrites
cheers -Dean Allum
avatar
Dan Costian November 23, 2012 11:33PM
Interesting article. However, the hollandite inclusions appear as stars (crystal spray) not as dendrites.
avatar
Stephanie Martin November 25, 2012 05:52AM
John, that is a spectacular graphite! And very appropriate since we just received our first signifcant snowfall of the season. Very pleased that you shared that one. Thanks for an unusual dendrite!

Dean, thanks for posting the link. Yes was aware of it but didn't think to post it, great that you did.

Dan, I too always wondered about those hollandite stars in quartz, if they qualify as dendrites? There are lots of dendrites that do appear star-like, but these particularly seem to be more acicular than stellate. Will have to look into that more.

Today I am sharing some samples of dendritic uraninite and schoepite from the Ruggles Pegmatite, Grafton, New Hampshire
approx 3 cm
end cut, one side polished



rough unpolished
open | download - P1390037(1)(1).jpg (457.8 KB)
open | download - P1390042(1)(1).jpg (491.3 KB)
avatar
Stephanie Martin November 25, 2012 05:59AM
More dendritic uraninite, along with the alteration schoepite group minerals including soddyite and fourmarierite.
ex Ben Shaub circa 1930.

Ruggles Pegmatite, Grafton Co, New Hampshire
approx 3.5cm both sides polished





alternate view
open | download - P1390059(1)(1).jpg (484 KB)
open | download - P1390069(1)(1).jpg (474.3 KB)
open | download - P1390075(1)(1).jpg (466.2 KB)
avatar
Reiner Mielke November 25, 2012 01:06PM
Can't get over the polished radioactives, talk about radioactive waste produced, gives me the shivers. Beautiful looking stuff that Ruggles mine dentritic uraninite though.
avatar
Stephanie Martin November 25, 2012 05:32PM
Thanks Reiner. Yes an interesting thought about the by-products. There were recently some large cabinet pieces of the cut material that became available and those were snapped up instantly, so there are some really nice museum quality cabinet pieces out there. The second piece above is pretty hot, we couldn't get a reading on my brother's cold war Russian geiger counter as the reading was over the capacity that it could count. I can't remember what the first one registered but it was less than the second piece.

regards,
stephanie :-)
avatar
Martin Rich November 25, 2012 05:47PM
Hi all!

Nice threat. In the pic below you can see dendrites of Graphite in Granulite. Orning near Melk, Lower Austria, Austria. 9 x 13 cm. Coll. & Photo Martin Rich.



Martin


"Komme gleich" ("I'll be right there") - Godot
open | download - Ordning bei Melk; Graphit.JPG (464.9 KB)
avatar
Martin Rich November 29, 2012 12:11AM
Hello!

The sample I show above has a wrong ID! This an old specimen (1900) from the collection of the Abbey of Melk, Lower Austria I swapt some weeks ago. It was labled as Graphite. After studying a lot of old literature, I´m sure this dendrites are Markasite/Pyrite. The austrian mineralogist MEIXNER analysed this in the 1950´s.

Sorry for the wrong ID.

Martin


"Komme gleich" ("I'll be right there") - Godot
avatar
Dan Costian November 29, 2012 02:01AM
Rick,
Two reasons pro manganese oxides: 1) shape; 2) the bluish diffuse color around which sometimes accompany manganese oxides dendrites.
One reason against: the metallic luster which might indicate some sulfides.
Now, what you show as Tiffany stone does not resemble as such. Google and ebay are full of pictures of that complex mineral which indeed consisted of fluorite (purple in this case), fluorapatite, bertrandite (berylium compound) yellowish and sometimes afghanite.
avatar
Rick Dalrymple November 29, 2012 03:22AM
Dan,
I agree they are probably manganese oxides based on color alone.

Tiffany Stone is not a mineral. It is a gem-term for the beryllium ore at (what is not) Wellman Resources. It is composed of bertrandite clay that is impregnated by ground water laden with fluorite, manganese, quartz (agate), and sometimes hylite opal. These have all been confirmed. I have never heard of afghanite being confirmed there but I have only seen one paper on it. The dendrites were confirmed as manganese oxides. The orange and peach colors are also caused by manganese.

There is also small traces of uranium salts that make the agate fluorescent. There is enough of the uranium that when the company was Brush-Wellman, they contaminated the ground water with the waste pile.

I have some more pieces I will try to get photographed tomorrow and post.


Stephanie,
Those uraninite et. al. dendrites are really cool. I have several specimen of that and now I want to polish them. But they are radioactive and the dust... but I want to polish them but they are radioactive... but I really want to polish them:-D What to do:-S

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Stephanie Martin December 03, 2012 03:17AM
Hi Martin, that is a nice sample of dendrites and thanks for the correction. My first thought was actually a silver or arsenide mineral but if this has been analysed then there is no guessing.

Rick, your indecision reminds me of Peter Griffin, just before he puts his finger in an electric pencil sharpener. Moral is, don't do it!

This specimen may look like aragonite but it is actually dendritic phillipsite.

Dendritic Phillipsite with some natrolite needles present in vugs
Höwenegg Quarry (Hewenegg Quarry), Immendingen, Hegau, Baden-Württemberg, Germany
79 X 33 X 30mm



open | download - P1410593(1)(1).jpg (431.3 KB)
open | download - P1410599(1)(1).jpg (418 KB)
avatar
Stephanie Martin December 03, 2012 03:25AM
This specimen is covered in dendrites but adding a bit of colour and interest to the mix is the additional aurichalcite. Both this specimen and one above from Robert Vaňo.

Dendrites on Quartz with Aurichalcite
Stříbrník, Nýznerov, Žulová, Jeseník, Moravia, Czech Republic
60 X 50 X 32mm





open | download - P1410528(1)(1).jpg (555.7 KB)
open | download - P1410533(1)(1).jpg (482.6 KB)
open | download - P1410546(1)(1).jpg (616 KB)
avatar
D Mike Reinke December 03, 2012 04:06PM
Rick,
Have you ever heard of phytoremediation for radioactivity? Sunflower plants clean up radiation. Google it, it's amazing what plants can take out of soil, all kinds of toxins. So plant a area of sunflowers, and do your polishing out in the middle of 'em, just don't breath...

Stephanie, great thread. Never realized they were so cool, and diverse. My first thought was more like ' been there, seen them...' thanks!
avatar
Rick Dalrymple December 03, 2012 09:13PM
Mike,

Thanks for that tip. Maybe they can use the technology to clean up some of the radioactive accidents around the world. Oh, and maybe nuclear power plants should plant them around the reactors in case of a leak;-)

I'll have to read more about this.

All joking aside, this does sound like it has potential. I wonder if it absorbs radon. Along the Wasatch Front, here in Salt Lake City, we have a huge pluton that produces some high levels of radon in peoples basements.

Stephanie,

Another great set of pictures. I hope to get some photography done tomorrow and upload more this week. I found my turquoise with dendrites finally.

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Dan Costian December 03, 2012 09:48PM
You are absolutely right Rick, Tiffany stone is a complex rock. I attached pictures from my collection.
open | download - Slide1.JPG (88 KB)
open | download - Slide2.JPG (72 KB)
avatar
Stephanie Martin December 04, 2012 12:18AM
Pavel, thanks for the photos. Did you confirm the pyrolusite by analysis? I have not found confirmations of true pyrolusite dendrites, most that were thought to be pyroslusite turned out to be managanese oxides. Any info would be great.

Best Regards,
Stephanie
avatar
Pavel Kartashov December 04, 2012 02:30AM
Yes, it was confirmed as some polymorph of MnO2, but nsutite or ramsdellite are much more rare then pyrolusite.
Microprobing show absence of cations other than Mn in the mineral. And wet chemical tests prove absence of Mn2+ in it.

Of course, initially these dendrites were formed as manganite or some other Mn hydroxide. But conditions in which the specimen was collected were extremely favourable for dehydratation processes - temperature of black rocks up to 60-70 Co on the sun, air moisture on 5 % level and low atmosphere pressure - heighth ~2000 m over a sea level. In other words, this pyrolusite is secondary.

Look also on not exactly dendritic but all the same very fanciful manganese mineral:
http://www.mindat.org/photo-472200.html
http://www.mindat.org/photo-472203.html
http://www.mindat.org/photo-472192.html
avatar
Stephanie Martin December 04, 2012 02:49AM
That is fascinating Pavel. Thank you for the explanation, this is helpful.

Interesting specimens and I am sure that we will learn more about the unnamed samples in future.

Best Regards,
stephanie :-)
avatar
Matt Wall December 08, 2012 12:48PM
Hi Stephanie and Everyone,
I got this nice Kasolite from Shinkolobwe from Leon Hupperichs today, and looking at the back it appears to have some nice dendritic Uraninite. I don't know if Uraninite can occur like this, I assume it does, but I'm not certain. See what you think, (pic attached). :-)
Kind regards,
Matt. :-)
open | download - Demesmae1.jpg (298.4 KB)
avatar
John A. Jaszczak December 08, 2012 08:50PM
Nomarski DIC images of stellate dendrite graphite overgrowths on a unique graphite crystal (#3270r) from the clintonite type locality, Amity, Orange Co., New York. (a) Overall view of the crystal (~1 mm field of view; 10× objective lens) showing approximately four generations of growth steps. The steps are relatively smooth and straight parallel to the <100> directions, but show stellate dendritic growths along the <110> step directions.
~1-mm field of view


The second image show close-up images of the stellate dendritic sections taken with a 50× objective lens. (Images taken with an Olmpus PME-3 microscope, Nomarski DIC prism and polarizers, and a Leica EC3 digital camera.)
~0.1-mm field of view


For more information an images see "Stellate surface features on graphite from Crestmore, California and Amity, New York." Mineral News vol. 28 #11 (2012).
avatar
Rick Dalrymple December 22, 2012 05:37AM
I finally found my turquoise cab with dendrites.

avatar
Rock Currier December 22, 2012 01:14PM
It looks like a manufactured material. However determining exactly what has been done to it if anything would likely cost much more than the stone was worth. Sort of like determining what sort of coloring treatment has been given to an agate. I can undoubtedly be done, but would you be willing to pay $100 to $200 to find out? If we get real lucky, the guy who did this particular kind of treatment will read this and tell us just exactly what was done to produce your kind of stone. But then, it may have been done in China by a guy who doesn't speak English and he probably works for a company that makes a living doing this kind of work. Who would want to break their rice bowl to tell you about your stone?

Rock Currier
Crystals not pistols.
avatar
Rick Dalrymple December 30, 2012 04:13AM
I don't understand Rock. What looks like manufactured material?

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Rock Currier December 30, 2012 05:07AM
Rick
It looks like no natural turquoise I have ever seen. That's why I suggested that it might not be natural. I may not be correct. We may get lucky and someone may come along here and say, "Yes, I dig that stuff out of my mine all the time and this is the locality." I hope I am wrong.

Rock Currier
Crystals not pistols.
avatar
Rick Dalrymple December 30, 2012 05:11PM
Rock,

Hey, I dug that myself. Really, I collected it at the Color Back Mine in Nevada in 2010. I polished it too. I have uploaded a bunch of specimens from the mine from when I was working with the mine owners and collecting there. Although, looking at the photo I can see why you thought it might not be natural.

If I had to take a guess it is a solid solution of turquoise and variscite, hence the odd color. There must be some silica in the mix as well. It is harder than most turquoise I have cut. This stuff comes in thin seams and when you tap on pieces they sound like glass.

The mine owners call it "blue ice" and they have been trying to market it for a couple of years now but they don't have much. They are asking $800 per pound for it (that is rough cleaned from matrix). I know they have sold several 1 to 5 pound parcels so it should start showing up in jewelry soon. I have about 2 five gallon buckets of rough from the mine and as I polish it I hope to find more dendrites in it.

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Rock Currier December 31, 2012 08:15AM
It might be interesting to pay for an x-ray of the stuff so you can find out exactly what the stuff is. If you are selling it for several hundred dollars a pound your customers probably deserve to know what it is they are buying.

Rock Currier
Crystals not pistols.
avatar
Rick Dalrymple December 31, 2012 03:42PM
Rock,
I am not selling it. The mine owners are TRYING to sell it for those prices. They haven't sold much in two years.

I was just saying that I collected some and have polished that piece. I only posted it because of the dendrites.

Mike, one of the mine owners, said it was all studied and identified by the "guys" at the school in Reno. I haven't seen any published papers on it.

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Rock Currier January 01, 2013 09:14AM
Rick,
Ask them if the school they are talking about is the school of mines and who were the guys.

Rock Currier
Crystals not pistols.
avatar
Rick Dalrymple January 01, 2013 04:16PM
Rock,
I believe it was somene from the school of mines, but I am not sure. I wont see them again for a few months but when I do I will ask.

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Rock Currier January 01, 2013 09:52PM
Sometimes these things are a mixture of minerals and not clear cut like turquoise, or chrysocolla and it is hard to give them accurate names. The market place demands clear names. So when something attractive in the way of a rock is found, it is given a new name that refers to that thing, like primavara stone, spinach stone, new jade etc. Even though the stuff may not be pure turquoise it is much better to call it turquoise for commercial purposes because of the preexisting name recognition. Even if it is clear cut like zoesite, the trade calls it Tanzenite because it has more sizzle and helps it sell better and it is now unstuck from the name of a common not very valuable mineral. So whats in a name? Well it turns out there is a lot in a name.

Rock Currier
Crystals not pistols.
avatar
Rick Dalrymple January 01, 2013 11:00PM
Rock,
I completely agree. A name is everything. THat is why they just call it "ice blue" turquoise.

Rick
I know I am in my own little world, but everyone knows me here.
avatar
Stephanie Martin January 02, 2013 02:35AM
John, awesome photos! Really interesting stuff. Thanks for posting those here.

Rick, that blue ice is surely cool! I am curious to know if it is a mix with variscite as may be suggested and if you can find out for sure.

My current laptop is running on full, so photos have been on hold until I get my new desktop set up shortly. But I have to start the New Year off right so here is a dendrite plate with a wish to all for a happy 2013.

It is rather long and difficult to photgraph well, and it my largest dendrite specimen to date.

Manganese Dendrites
Kagawong, Billings Township,
Manitoulin Island, Ontario, Canada
31 x 9 x 3.5 cm



open | download - P1410687(1)(1)(1).jpg (355.5 KB)
open | download - P1410715(1)(1).jpg (695.1 KB)
avatar
Alex Homenuke January 02, 2013 03:31PM
Turn it about 160 degrees counterclockwise and it has the same general shape as Manitoulin without the inlets
avatar
Stephanie Martin January 03, 2013 02:36AM
I must admit I was tempted to photograph it that way but thought it was my overactive imagination again. I guess I'm not the only one who has that problem ;-)

cheers,
stephanie :-)
avatar
Rock Currier January 03, 2013 08:35AM
This may be the greatest accumulation of images of dendrites ever made. Its a shame that most of them are here only as attachments and not uploaded to our image bank.

Rock Currier
Crystals not pistols.
avatar
Bill Cordua January 03, 2013 06:06PM
Here are dendritic iron? manganese? oxides in a flake of muscovite. Don't know the locality. field of view is about 2 cm. Took this with my Dino-Lite, backlit.
open | download - MuscoviteIncl.jpg (135.5 KB)
avatar
Don Windeler January 03, 2013 08:26PM
Rock:

Your reminder about including these in the image bank is always a good one; unless it's something off topic or goofy I usually try to post in my gallery first.

I'm curious as to recommendations for the best approach in this particular thread, though. Setting aside the clear-cut examples where the minerals are known, there are a lot of cases of "dendritic Mn-oxide schmutz" where someone probably took a pic more for aesthetics than as a mineral. How best to tag these, especially when this stuff can show up anywhere and usually isn't included in the locality listings?

I may have partly answered myself, though; as I poke around, I see "Manganese oxides" is a catch-all bucket option one could use.

Will try to contribute some of my own soon -- I picked up a few interesting things on the Morocco trip that haven't made it in front of a camera yet.

Cheers,
D.
avatar
Geoff Van Horn January 04, 2013 03:22AM
Romanechite dendrites on microcline from the Wausau Pluton in Marathon Co, Wisconsin. I accidentally collected this in June of 2012. I was digging smokey quartz and Wausau moonstone (anorthoclase) and this was attached to a very nice smokey cluster. I knocked this part off with my hammer before noticing the dendrites.

http://img.photobucket.com/albums/v737/airborne200208/0fe54383c60d040f25670c571678c3e1.jpg
avatar
Rock Currier January 05, 2013 09:54AM
I have created a thread in Best Minerals and a stub of an article for Dendrites. Would someone here like to work on it and complete the first draft of the article on dendrites?

Rock Currier
Crystals not pistols.
avatar
Stephanie Martin January 05, 2013 03:51PM
Rock I have been going through the galleries and selecting some fine examples which I will link into this thread eventually.
I planned to do an article on dendrites but maybe I will just work on it as a Best Minerals project instead as likely can incorporate much of the information into that format. Thanks for thinking of doing it as a Best Minerals topic.

regards,
stephanie :-)
avatar
Rock Currier January 05, 2013 08:41PM
Stephanie, I would encourage you to work on the best minerals article. There is a lot of good information there that should be buried in old thread postings. Just go to the Dendrite stub under D best minerals and in the message field like you find at the bottom of all of these thread pages, just start working. Just start to do something there, and Ill set up the basic format in your message to help you along and then you can add, cut or edit what ever you want. If you stick through the process till the end and do another best minerals article, Ill make you a moderator. By the time you finish a rough first draft on dendrites, you will know if doing best minerals articles is something you enjoy doing. Ill be around help and advice if you need it.

Rock Currier
Crystals not pistols.
avatar
Roger Curry January 06, 2013 12:06AM
Stephanie, I would love you to do this.
Regards
Rog
avatar
Don Windeler January 06, 2013 03:07AM
I love the "Best of..." series, so it'd be great to see this thread form a kick-off. (And thanks for your enthusiasm, Stephanie!)

So here’s my contribution for the day to the thread, both pictorial and informational. Back in 2008 I was thrilled to purchase this piece, labeled as native copper inclusions in gem chrysocolla from Arizona. (4.8 x 3.0 x 0.6cm, imaged with a cutout of white paper behind it using a Canon photocopier. Will upload to my gallery and include a link here when approved – sorry it’s not a better shot.)

copper dendrites in agate

Not quite, it turns out. Si and Ann Frazier saw the piece at a club meeting and told me the dendrites were artificially added. Apparently there was a gent in Phoenix named Paul Rabbit who’d developed a process to induce copper or tin dendrites in agate, by soaking an agate in a Cu or Sn solution, then putting it in contact with a piece of iron to force precipitation. (I’m oversimplifying, as it apparently took the guy over six years to work out the right way to do it.) He called them “Fischer stones” after Dr. George W. Fischer, who’d self-published a book in 1991 called “Gemstones and chemicals: how to create color and inclusions.”

The source material was “snakeskin” agate from eastern Oregon. According to the Fraziers, this agate is microgranular and has randomly-oriented fibres, which makes it more amenable to the dyeing and dendrite-production process. Since then I’ve bought a Malheur County, OR, nodule of the same from Dana Slaughter, pictured below. (6.5 x 5 x 6.5 cm, also soon to be posted in my gallery.) This picture was taken by Dana and is used with his permission. While not obvious in my picture above, the edges of the polished slice look a lot like the rind on this snakeskin nodule.

Snakeskin agate, Malheur Co., Oregon

The above info on copper dendrites in agate is summarized from a few paragraphs in a Lapidary Journal article the Fraziers had written, cited below. I don’t actually have the article, just the paragraphs Ann sent me, but it sounds like required reading for this thread!
Frazier, Si and Ann (2002). Dendrites: Nature’s Line Drawings. Lapidary Journal 32, 2-02. (sorry, I’m going off an internet search and am not sure on the volume / page numbering...)

Cheers,
D.





Edited 1 time(s). Last edit at 01/08/2013 05:15AM by Don Windeler.
open | download - 20080115_copper-in-agate_Oregon.JPG (41.7 KB)
open | download - 20120211_agate_RomeMalheurCoOR.jpg (56.7 KB)
avatar
Rock Currier January 06, 2013 10:51AM
Don, the only images we use in Best Minerals are those that are uploaded formally to the Mindat gallery. The uploading process required that the uploaded specify the copyright type that will apply to the image. Without the copyright specification we are reluctant to use them in best minerals. That's why I continually request people to upload their images rather than just attach them to thread posts.

Rock Currier
Crystals not pistols.
avatar
Don Windeler January 06, 2013 06:34PM
Sorry if I was sloppy in my verbiage, Rock. I wasn't actually proposing the pic above as a "Best of Dendrites" when referring to my contribution, more just was adding to this ongoing thread. I figured the Fraziers' LJ article might be of interest.

I am going to post the pics later today and will link them in when approved -- I just had the inspiration to write down some things after remembering this piece and didn't want to wait around until they were approved to post my comments.

But I sympathize with your frustration at great pics that never make it into the galleries!

Cheers,
D.
avatar
John Truax January 07, 2013 03:18AM
This malachite egg belongs to a friend.

Interesting thread .... thanks all.
open | download - malachiteegg.jpg (272.5 KB)
avatar
Stephanie Martin January 07, 2013 04:55AM
John T. that is a lovely feathery malachite egg! And yes those fibrous malachite specimens qualify as dendrites as can clearly be seen in the egg. I have never seen one polished like that before, rather unique I should think. Eggxellint! :-D

Geoff - that was a happy accident I'm sure (previous page). Nice that you decided to keep the dendrite and share it here. Enjoy it.

Don- great info! And intrigued about those artificially induced dendrites! Your piece reminds me of the copper mineral? dendrites in Dominican Republic pectolite/larimar. I am looking forward to seeing your dendrites from Morocco. One of our club members was at the conference and showed us their trip, and one spot specifically where dendrites littered the ground!

Thanks to all for continuing to contribute to this topic!

regards,
stephanie :-)
avatar
Don Windeler January 08, 2013 05:17AM
Gallery entries now linked in above message.

Cheers,
D.
avatar
Rick Dalrymple April 12, 2013 09:37PM
This is lepidolite and I think the dendrites are feldspar but they could be beryl.

Unfortunately, I didn't get to keep this specimen. I only got the hold it for a minutes.



Rick
I know I am in my own little world, but everyone knows me here.
Sorry, only registered users may post in this forum.

Click here to login



bannerbannerbannerbannerbannerbanner
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: April 30, 2017 06:15:22
Go to top of page