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Identity Helpif you know Elmwood Tennessee or hydrocarbons, pls review

15th Nov 2013 22:30 UTCTony Peterson Expert

I have just uploaded a very odd image:

http://www.mindat.org/photo-571787.html

which is a closeup of a routine Elmwood fluorite/sphalerite/dolomite specimen. It has numerous globules and patches of a tarry hydrocarbon on one side, not rare of course, but a couple of these seem to have sprouted flexible whiskers of either carbon or a dark, solid hydrocarbon. Comments, please!!!

Tony

15th Nov 2013 23:44 UTCDan Costian

I know nothing about Elmwood, but a lot about hydrocarbons. Hard to believe that the threads are solid hydrocabons (or carbon fibers as well).

I've never seen such shape of solid carbonaceous inclusions like bitumen or asphalt (aka anthraxolite); they look different.

16th Nov 2013 00:33 UTCTony Peterson Expert

I can only agree. But they they don't look man-made; how would they get attached to the hydrocarbon patches? I think I might be able to get a higher-res image of the attachment points.

tony

16th Nov 2013 00:51 UTCReiner Mielke Expert

There seem to be some white fibers as well

which makes me think that what you have is "lint" that has gotten stick to the tar. In other words some sort of synthetic fiber.

16th Nov 2013 03:42 UTCTony Peterson Expert

The white fibers are indeed man-made. That doesn't speak to the black ones. The white ones can be anywhere on the specimen. The black ones come out of the tar patches. I would put this in an SEM if it would fit....

16th Nov 2013 10:59 UTCReiner Mielke Expert

Pull on one and see what happens. My bet is they are manmade fibers and will stretch. Also as far as I can see from the photo not all the fibers start at the tar patches.

16th Nov 2013 14:34 UTCDavid Baldwin

Reiner, If you look and follow them carefully, they do ALL originate in the tar. The only exception is the one on the left which is probably from a tar patch out of view. The main cluster top right has 5 fibres coming out of it and there are 5 terminations, one of which is behind a sphalerite crystal.

Tony, Great photo by the way. Deserves to be a POTD!

16th Nov 2013 16:19 UTCDan R. Lynch

What a fantastic photo (the stereo view is truly awesome)! However, I do share a little of Reiner's skepticism. I think sacrificing one fiber wouldn't be a bad idea, to see if it's flexible or brittle, or if it stretches, etc. It could be possible that they're just heavier, thicker manmade fibers that only remained on the specimen because they stuck to the tar, as opposed to those little white fibers which stick everywhere because they're so fine and often statically charged. But I'm just playing devil's advocate here; I'd really like for them to be natural, but because they're so odd, it's worth testing them a bit.

16th Nov 2013 16:25 UTCDavid Von Bargen Manager

It is a very good picture.

If you look at the grey material, it does appear that they are very uniform in width - between fibers and along fibers. They also appear to have a similar cross section (sort of looks like they are thick in the middle and thin down to some fairly thin edges). If the cross sections are all alike and not a rectangular or square cross section, they probably are not natural.

16th Nov 2013 16:54 UTCDan R. Lynch

Another thought I had was with the "terminations" you can see on three of the fibers. They're all identical, which of course could be indicative of some form of crystal termination, but you could also imagine a similar result if a machine were trimming fabric or threads.

One last thing I noticed: the lowest fiber in the image appears to be laying across the tar blob, rather than extending out of it. You can see both ends of the fiber, to the left and right of the tar, as if it is stuck to the tar at a midpoint along the fiber rather than at one of its ends.

16th Nov 2013 17:14 UTCTony Peterson Expert

It's tough to see all of starting points because the image isn't as good as you all claim (I will try to get a better one) but all of the fibers do originate in one of two tar patches. What I can do is remove one and get it into an SEM. One SEM image should settle the issue, it should be easy to distinguish between natural and unnatural. Either way, they are very odd. If I can establish they are anthropogenic, I will ask Mindat to remove the image.

I am, however, pretty confident that the hydrocarbon patches are natural.

tdp

19th Nov 2013 03:33 UTCTony Peterson Expert

I have added a higher-res image and its stereo counterpart to this group of photos. The stereo image in particular very clearly shows how the unusual fibers are attached to the hydrocarbon patch:

http://www.mindat.org/photo-572543.html

I have examined these closely in a stereo microscope and in fact they are largely transparent, with a blue-grey coloration. I am no closer to understanding their origin.

Tony

19th Nov 2013 07:03 UTCD Mike Reinke

Where they touch they don't appear to stick to each other, do they? And the two lower ones, at about "6 o'clock" seem to run almost parallel, then turn to the viewers' left more than 90 degrees, might that mean anything? Very weird!

19th Nov 2013 15:05 UTCVincent Rigatti

Is there any chance it could be silver? Has a metallic appearance. not sure if that is consistent with the area mineralogy...

19th Nov 2013 17:31 UTCRob Woodside 🌟 Manager

Transparent??? Time for a x-ray.

19th Nov 2013 17:41 UTCMaggie Wilson Expert

galena whiskers... ?

http://www.minersoc.org/pages/Archive-MM/Volume_57/57-387-231.pdf

In the lead-zinc deposits of the Rhodope Mountains, Bulgaria, however, unusual elongated straight, as well as crooked and irregular needle-like galena crystal formations and whiskers also occur.

23rd Nov 2013 17:44 UTCDoug Daniels

A stretch, but the POTD (Nov 22) shows marcasite; it looks similar, although those are much shorter. Maybe similar to pyrite wires?

24th Nov 2013 16:05 UTCTim Jokela Jr

Clearly lintite.

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