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Identification Help (Native Bismuth)

Posted by Joe Mork  
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Joe Mork July 18, 2012 06:41PM
Hello! I was recently at a flea market in eastern Ohio as I live in the town of Sharon, PA which is close to the Ohio border. Anyways, I am an avid rockhound and collector, and have my BA in Geology. While at the flea market I purchased a glass canning jar full of Amber, Agate, and what I am almost positive as being Native Bismuth. I have ran every text imaginable here at home, but I would still like to be sure. Now I know the nearest mineral museum is that at Youngstown State University who may look at it, but I haven't asked yet. Does anyone know of anything else I can do?
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Rock Currier July 18, 2012 07:30PM
If you ran every test imaginable, that doesn't leave much to imagine. Did you run a specific gravity test? What was the result? Melting point?

Rock Currier
Crystals not pistols.
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Peter Haas July 18, 2012 07:33PM
Please post a photo and/or tell us which tests you tried and what were the results.
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Joe Mork July 19, 2012 11:09PM
Maybe not "every" test imaginable, but only those tests in which I could perform in my own home with the tools on hand. I apologize I am lacking pictures as I will attach them either later tonight or tomorrow.

Color: Metallic, almost a silver-white. Under the view of a microscope 2 samples contained very small vugs or openings. Within those openings the walls were an iridescent/metallic color to that color of the Hopper Crystals (rainbow). Also as with the picture, 1 sample contained a blue hue while looking at it, however through a microscope that blue hue is accompanied with other colors resembling those colors of the Hopper Crystals (a rainbow tarnish if you will) as well.

Streak: Silver-white

Hardness: Between a 2 and 2.5

Cleavage: Perfect in one direction

Fracture: Uneven and jagged

Specific Gravity: Between a 9.7 and 9.8

Crystal System: Hexagonal, some in the small vugs or openings are almost branching
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Reiner Mielke July 20, 2012 12:49AM
Sure sounds like bismuth to me, however if you have small vugs with crystals in it, it is likely man-made bismuth. I don't know of any natural chunks of bismuth with vugs that contain crystals.
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Peter Haas July 20, 2012 12:52AM
Bismuth is mostly more or less yellowish, but can also be light grey/silvery grey with no tad of yellow. Hardness and, more importantly, density also match well. When you say that cleavage is perfect in one direction, but fracture is unven and jagged, I assume that you have an aggregate with lamellar structure and that you have observed the parting of individual lamellae rather than the true cleavage (otherwise, an uneven and jagged surface would not make much sense when the cleavage is perfect). Lamellar aggregates are well known of native bismuth. What also comes to mind, as an alternative, is antimony, but this has a much lower density (ca. 6.8 g/cm3).

Thus, what you have appears to be bismuth. To be more conclusive, I need to see a picture, though.

EDIT:
A lamellar structure, if it is not particularly tight, also explains why you see "vugs" with crystalline structures in them. Thus, this observation does not necessarily mean that it is man-made.



Edited 1 time(s). Last edit at 07/20/2012 12:55AM by Peter Haas.
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Joe Mork July 20, 2012 01:53AM
Peter,

3 pictures are coming in 3 different attachments which includes this one because of their size
open | download - 1.JPG (944.3 KB)
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Joe Mork July 20, 2012 01:56AM
2nd picture
open | download - 2.JPG (896.4 KB)
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Joe Mork July 20, 2012 02:02AM
3rd picture

If you need better I will try again in the morning. I wish I could show you the vugs, but my microscope isn't capable of capturing images.
open | download - 3.JPG (941.5 KB)
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Pavel Kartashov July 20, 2012 10:53AM
This is 100% technical product and it is more similar to antimony then bismuth.
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Lefteris Rantos July 20, 2012 02:05PM
I agree it's certainly man-made/industrial product. The bright silvery color is also more consistent with native Antimony; Bismuth has a characteristic pinkish tint.

Lefteris.
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Uwe Kolitsch July 20, 2012 04:09PM
I also agree.
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Evan Johnson (2) July 20, 2012 06:10PM
I don't disagree with all of you based on pictures, but what accounts for the density readings being off by about a half?
EMJ
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Donald Slater July 20, 2012 06:59PM
It almost looks like galena to me. I have seen weathered galena that has a patina similar to this. The crystals look more like isometric instead of hexagonal, there is one in particular that looks like it has a pyritohedron face and the others look more cuboctrahedron. I probably have those terms wrong. My crystallography is rusty. The main problem is the density. It is seems too high. Maybe the density should be recalculated.
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Joe Mork July 20, 2012 07:13PM
I'm sorry I have to disagree about this being man-made and I have seen native Bismuth in this exact color and form. If indeed it was man-made that would not constitute the small vugs with rainbow colors which would tell what vugs in Bismuth to where crystals are formed are found. I have seen a lot of slag in every color and shape living near the Steel City of Pittsburgh and in the middle of coal country and I can tell you this is not it. At best I can take it to a local museum to be analyzed. I was very skeptical myself on the fact of what it could be. I ran another density test and came out with the same number.
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Evan Johnson (2) July 20, 2012 08:08PM
The density being precisely that of pure elemental bismuth despite the material being admittedly somewhat vuggy suggests positive confirmation bias to me.
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Reiner Mielke July 20, 2012 11:39PM
It does not look like bismuth to me. The cleavage is too weak and the colour is too silvery. However the cleavage is also too weak for antimony, maybe it is some sort of alloy. Send it out for EDS that should settle the matter.
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Alfredo Petrov July 21, 2012 01:20AM
I agree with Evan and Reiner. I wouldn't be surprised it it turns out to be an alloy and not a single element.
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Rob Woodside July 22, 2012 05:42PM
'Technical Product" Pavel nailed it.
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Joe Mork July 22, 2012 05:59PM
Thanks for the input and help. Gonna be taking it to YSU on the week of the 1st. If it is a man-made product I would like to know what
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ryan christensen July 22, 2012 06:14PM
Looks like Skutterudite to me!
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Rowan Lytle July 22, 2012 07:24PM
My first thought at seeing the pictures was galena.

-Rowan Lytle

Necessities:
Food, Water, Shelter, Fire, Minerals.
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George Creighton July 22, 2012 09:04PM
Also thought galena

Regards george
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Reiner Mielke July 22, 2012 09:10PM
Seriously guys, Galena would never break like that ( has a perfect cubic cleavage) and the color is totally wrong. Check your mineralogy books!
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John Lichtenberger July 23, 2012 12:41AM
here's a big chunk of Bismuth for comparison... typical tarnish and all

http://i3.photobucket.com/albums/y62/auplater/Bismuth1.jpg

auplater
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Joe Mork July 23, 2012 01:38AM
Thank you for the comparison photo. The stuff I have is definitely not Bismuth, but does in fact look like Skutterudite. The picture attached shows exactly what I see in the vugs as well. I will also attach a picture of the octrahedrenal crystals that come off.
open | download - 0507221001203856999.jpg (199.3 KB)
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Tim Jokela Jr July 23, 2012 03:48AM
Does nobody ever consider testing with Occam's Razor in cases such as this?

Genuine natural native bismuth, unlabelled, unboxed, in a jar with agates and amber???

Add the fact that it looks NOTHING like either native or manmade bismuth... and I collected semi-metals for a while, have seen lots...
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Philip Perkins July 23, 2012 06:50AM
Peter was close when he said Bismuth has a yellowish color, i have seen many Native Bismuths from Wolfram Camp, North Queensland,
& i'd say Bismuth has a light brassy color like is shown with John's specimen.
Yes Bismuth does crystallize, i once saw a specimen in combo with Quartz in the Queensland Mines Dept collection in Brisbane, many years ago.
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Evan Johnson (2) July 23, 2012 12:52PM
So the density was just fictional then?
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Joe Mork July 23, 2012 01:52PM
No, the density on the largest piece was just as I said. I'm rerunning the entire test
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Reiner Mielke July 23, 2012 04:40PM
If the SG isn't fictional than it can't be skutterudite. The Hardness is also off for skutterudite. I think it is a type metal alloy ( Pb,Sb,Sn).



Edited 1 time(s). Last edit at 07/23/2012 08:01PM by Reiner Mielke.
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Evan Johnson July 23, 2012 06:41PM
Edit: Comment no longer relevant.



Edited 1 time(s). Last edit at 07/27/2012 12:35PM by Evan Johnson.
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Simone Citon July 26, 2012 12:51PM
Hi Mork, how are you and Mindy? winking smiley
Seriously, Joe, to me no man-made product of native elements (another morphology, generally more cleavaged), no crystallized natural Antimony or Bismuth (really in euhedral crystals too much rare), I see pentagonododecahedral crystals pale gray color with bluish iridescence on the surfaces and I'm thinking to the moroccoan Skutterudite. See you that
http://www.mindat.org/photo-41615.html
Before you come back on your test, there may be a link with moroccoan minerals? Maybe at the flea market there were other pieces, as Baryte, Vanadinite, Azurite / Malachite, Chalcedony, other Morocco material?

Simone Citon
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Yan Beaudet July 27, 2012 06:14AM
hi , look man made to me but if it's natural could it be a kind of antimony minerals like senarmontite with bluish irisations of berthierite ?
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