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GeneralBent, deformed or strange crystal habits new version

23rd Oct 2019 18:37 UTCRolf Luetcke Expert

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It was suggested the old thread was too long so I start another since it was a cool thread and lots of interesting habits of crystals.
To continue from the other one, this is the other odd habit of wulfenite I had found at the San Diego Mine by Tombstone.   Again, a lot of study finally showed me it was a wulfenite.

23rd Oct 2019 18:38 UTCRolf Luetcke Expert

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This one was another interesting habit that I had not seen before in wulfenites.  Seems this mine has a number of odd habits.

23rd Oct 2019 19:53 UTCJeff Weissman Expert

Rolf - if you look at wulfenite #8, under "Crystallographic forms of Wulfenite" on the  wulfenite page , the habit illustrated is very similar to the second one, a truncated pyramid with a hemihedral morphology

23rd Oct 2019 21:13 UTCRolf Luetcke Expert

Jeff,
Thanks for the crystallographic info and will certainly have a look.
I love wulfenite and have a few drawers full of the wide range of habits.  

23rd Oct 2019 21:16 UTCRolf Luetcke Expert

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Here is another odd wulfenite from SE Arizona.  This one is also quite small, 4mm field of view.  When I first found it the color and habit reminded me of mimetite until I zoomed in on the ends of the crystals and saw they were four sided.  This one seems to have formed in a "bow tie" habit.  It is from the Gallagher Mine, near Tombstone.

23rd Oct 2019 22:05 UTCPaul Brandes Manager

Yes Rolf, thank you for restarting a new thread about this fascinating subject. The original thread was getting too long and unwieldy so a new one was in order......

24th Oct 2019 15:51 UTCDan Owens

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Looking at all of the pictures of bent minerals reminded me of this photo I took of an unknown crystal a while back. Sorry about the image quality. A guess at ID?
 

24th Oct 2019 17:17 UTCRolf Luetcke Expert

Dan,
I have a lot of things like this too, also anyones guess as to what it could be.  Location is important to determine what it could be.   Fibrous minerals can be a lot of things, byssolite comes to mind, various forms of asbestos, chrysotile another example, palygorskite another but the association is important as well as locality.  More info is needed before we can make any educated guesses.

23rd Nov 2019 06:26 UTCV. Stingl

Dan, to me it looks like something organic. Could this be possible?

25th Oct 2019 00:46 UTCDan Owens

Rolf
Was found in an intrusive formation in metagraywacke. I have seen other fibrous minerals. I also thought of asbestos.

25th Oct 2019 21:09 UTCEric He

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Ochahedral and diploidal modification on a corner of a pyrite cube/pyritohedron mix.

22nd Nov 2019 14:16 UTCRolf Luetcke Expert

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This piece is from the Leiser Ray Mine, in California and the field of view is 6mm.  The most crystals are a normally straight habit but one in the mix was quite curved in its growth.  The other mineral involved is an iron oxide, probably hematite.

22nd Nov 2019 14:22 UTCRolf Luetcke Expert

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This one was very odd to me.  Unfortunately it is very tiny but when I saw the glint from this pocket, I put it on the highest power.  The pocket has a colorless quartz crystal growing in it and the dark mineral is hematite.  The odd thing is that the hematite selectively grew on some of the quartz faces and not on others, following the face edge faithfully.   I scratched my head as to why the hematite coated only some faces and not others.  Had never seen this before.  The other thing is the black hematite was silvery with a mirror like reflection when the angle of light was changed.  Wished it had been a larger piece but one can't choose what comes along.

24th Nov 2019 16:01 UTCEd Clopton Expert

My (c)1978 Audubon Society Field Guide to North American Rocks and Minerals shows a picture, fig. 184, of quartz from West Haven, Connectictut, with red hematite coating alternating terminal faces of quartz crystals.  I assume it has something to do with the physics & chemistry of opposite ends of the rhombohedron crystal form--the six faces of the quartz termination are a combination of intersecting positive & negative rhombohedrons, alternating +, -, +, etc. around the termination--whereby under certain conditions one end allows hematite to attach and the other end doesn't.  Can somebody who knows more about this than I do weigh in?

28th Nov 2019 13:27 UTCRolf Luetcke Expert

Ed,
Just looked in our personal library and I have a ton of mineral books but don't have the Audubon book on minerals.  Enjoyed reading your description of the positive-negative rhombs. and the possible reason for the deposition on certain faces and not others.  I also would like to hear if anyone else chimes in.  Your points sure make some sense as to this situation.
Wish the piece had been larger to get a better photo since it was such an interesting situation.
I will see if we can find one of the Audubon books to have a look.  
Thanks for adding this.

22nd Nov 2019 14:25 UTCRolf Luetcke Expert

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The last piece from the Leiser Ray Mine, as the one above is also.  
This piece was a flat surface of quartz that was partly frosted by what I assume was another color of quartz and on this were tiny specks of hematite crystals.  The ones on the left show the silvery reflectivity when the light was right and the ones at right show the black color with no light on them.   The fov here is 4mm.  The one above is only 3mm field of view.

24th Nov 2019 16:11 UTCEd Clopton Expert

Here's a truly bent crystal, a crystal of beryl embedded in smoky quartz from the Consolidated quarry, Georgetown, Maine.

Tectonic forces broke the crystal into 5 sections as seen as the pegmatite cooled, and the gaps later filled in with quartz.  I have a larger, rougher beryl specimen from an unknown locality in the Black Hills, South Dakota, with an identical bend (and coincidentally also 5 sections).

27th Nov 2019 14:35 UTCRolf Luetcke Expert

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Here is an odd piece from Crystal Park Colorado I found yesterday.   The very long crystal is an unknown but I tested it for hardness and it is harder than steel so I assume this is a strange quartz.  The crystal by it is microcline and some iron mineralization also in the mix.
The crystal is certainly not like any quartz I have seen.  If anyone else has an idea if it could be something else, please feel free to comment.  Photo is 15mm top to bottom.

27th Nov 2019 14:45 UTCRolf Luetcke Expert

Just took a close look at the crystal under the highest power on my microscope and the crystal has only 4 sides so not a quartz.  The sheen is just like the microcline next to it and I wonder if this could be a microcline?   It is definitely 4 sided though.

27th Nov 2019 16:25 UTCRuggy Holloway

Looks like Tessin habit quartz from photo

27th Nov 2019 22:58 UTCRolf Luetcke Expert

Ruggy,
You know, after you said that I did take another look and sure enough, on the edges of the sides, very thin but visible, I could see a crystal face.  The tip, on the back side, also has crude but visible other faces.
On the Quartz page it does list another habit also but it sure does fit all the things making it a quartz.  I had not seen one anything like it before.

28th Nov 2019 13:30 UTCRolf Luetcke Expert

Ruggy, 
Looked on the Quartz page and there is another habit called "Muzo" habit and it does resemble the specimen I have even more.  Have to try and do a bit more research on that.

27th Nov 2019 23:01 UTCRolf Luetcke Expert

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Here is another very odd quartz from the Crystal Park location in Colorado.  This was a break along a surface and on the break it showed quartz but not as complete crystals I found in other places but in hollow places, centers filled with the microcline they are in.  The quartz has a bit of a smoky color.  Image is 6mm across.

28th Nov 2019 01:19 UTCKevin Conroy Expert

It looks a bit like graphic granite.
 
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