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Mineral PhotographyUnknown mineral refuses to be photographed

8th Jan 2015 17:30 UTCOlivier Langelier

Hi,

There is a mineral I'm trying to observe but it just wont reveal itself. It's about 2mm in size. When seen from

a distance it looks yellow and transparent, but up close it looks like a totally different grain.

First I will admit that I do not have the best equipment. All I can afford right now is my Canon 300HS and

a ridiculously cheap usb microscope. Despite this I usually get very acceptable results.

I thought that my equipment was to blame so I made a test with a grain of crystal clear quartz and the result

is normal so I'm left to wonder, could the mineral be to blame? What could do this?

8th Jan 2015 17:34 UTCReiner Mielke Expert

Looks like quartz to me. How hard is it?

8th Jan 2015 17:36 UTCOlivier Langelier

The second picture is quartz yes it was to show my equipment is not that bad.

The crystal is too small I cant do much with it.

Are there minerals known to be difficult to photograph?

8th Jan 2015 18:49 UTCReiner Mielke Expert

The first picture looks like quartz as well. Clear minerals with shiny surfaces are very difficult to photograph.

8th Jan 2015 19:30 UTCOlivier Langelier

I think you're missing the point here, if it was quartz I'd be able to take an image as clear as

the actual quartz picture I took. And if anything it looks much more like a zircon than quartz

Most importantly, I'm asking about minerals difficult to photograph to have a discussion, not

an identification

8th Jan 2015 19:48 UTCReiner Mielke Expert

? I can't see any fundamental difference in the quality between your two pictures.

8th Jan 2015 20:07 UTCOlivier Langelier

Ok I can put it this way; if the mystery crystal looks transparent and dark in the first picture it

should also look transparent and dark in the other. But somehow it doesnt, it looks blurry and

pale. It seems very plausible that this is caused by a property of the mineral. In the picture of

the quartz fine details of the surface can be seen despite reflections and irregularity and it looks

the same from any distance

8th Jan 2015 20:29 UTCReiner Mielke Expert

More light on the grain in the closeup and poorer resolution would cause that.

8th Jan 2015 21:01 UTCOlivier Langelier

Yeah sure whatever..... (td)

8th Jan 2015 22:23 UTCNorman King 🌟 Expert

It seems to me that the lighting is different. Or the processing. I cannot tell that what you show in your close-up box is the same as where you show it came from. A lighting issue could cause that difference. More or less relief, more or less reflection, maybe some refraction (internal).

8th Jan 2015 23:13 UTCKeith Compton 🌟 Manager

Hi Olivier

As mentioned by others earlier, lighting can be the cause. Not sure if I can explain this very well but .. while you have taken a pic of a Quartz - in the same light as the original - the quartz is a uniform colour. The original specimen is dark, when you then move closer in to the original specimen - in the same lighting conditions - the light getting to the lens lessens and you have to open the aperture on the camera to allow more light in. You may have also changed the the angle a little (it does look a bit different) which will also change the light.

As for your other question as to minerals difficult to photograph - for me - Dioptase, very transparent quartz (reflections).

I am intrigued as to how you photoshopped or made the original image with the close-up pic with lines indicating where the close-up was on the specimen.

Cheers

Keith

8th Jan 2015 23:30 UTCOwen Melfyn Lewis

Olivier,

Your main problem is a lack of sharpness in the image. This is present in both images, just worse in the second than in the first.

It is not possible to say why this, only that there is no reason at all to expect it to be the same in the images of two different subjects.

Test for the following:

1. Is your specimen support and camera support *absolutely* vibration-free?

2. Is the point of critical focus exactly on the small area of the specimen that you are trying to capture. Are you sure your camera can do do critical focusing on a small area of a relatively large specimen? If it can't, then the sharpness of any such image you make is going to be a matter of pot-luck.

3. Will your camera allow you to set the aperture and then automatically adjust the exposure time to balance that aperture setting for whatever the available illumination may be? If so, you need to fix your aperture to f/8 or f/11 (experiment to see which gives the better (sharper) result), letting the time of exposure go out even to several seconds if need be. If your camera will not give you control of this, that's another uncontrolled image quality issue you are fighting.. Your only counter (other then a better camera) is more powerful and *well diffused* lighting . But by whatever means, you need for get the aperture reduced to f/8 - f/11 for the best sharpness

4. Every camera and microscope system has limits on the resolution it can achieve. Are you sure that your cropped image is within the spec of your optics and sensor plate to produce a sharp image?

Only you can find what your problems are. Tackle the the possible causes one at a time and, I suggest, in the order they are given here and do what you can to reduce/eliminate them.

As the old prayer goes:

'God give me the strength to change those things I can,

the patience to endure those things I cannot change.

- And the wisdom to know the difference'.

9th Jan 2015 00:01 UTCOlivier Langelier

All the conditions are exactly the same including the exact same light.

I didn't post them all but I tried dozens of times from different angles or with

different lighting and it's not better at all.

I made the close up image with microsoft paintbrush! Simple copy past

then added frame with the box tool.

The first image with highest resolution comes from my Canon camera and

clearly shows the mineral as transparent, dark and yellow. The other image

comes from the microscope, but so does the image of the quartz grain.

The only thing I'm certain about is that the problem occurs only with this

particular specimen and no other.

I know of only one mineral that is notoriously difficult to photograph, was just

wondering if there were others

9th Jan 2015 01:39 UTCAlex Homenuke Expert

It looks like a reflectivity problem to me. I get the same thing occasionally with fracture surfaces on sulfides. Try more diffuse light - even a piece if tissue paper over your light source. Changing the plane you are focusing on may also make a difference.

9th Jan 2015 02:07 UTCKeith Wood

Perhaps it is shy. Or possesses unique metaphysical properties.

Or maybe the conditions are not exactly the same, as you suppose. If there is a difference, something must be changing.

What is so interesting about it that you are trying so hard to get a picture of it? It looks like quartz in a rock with garnets.

9th Jan 2015 10:05 UTCOwen Melfyn Lewis

Olivier,

You have the same basic flaw in both images, just a little more acutely in the first than the second. but present in both. A lack of sufficient sharpness for the image size..

There are no 'bad' stones - only bad photography. That said, photographing stones is more demanding of man and equipment than is taking snaps of the kids on the beach..

9th Jan 2015 16:45 UTCRolf Luetcke Expert

Olivier,

To face your question straight on - Yes, some minerals are hard to photograph. I believe I have taken tens of thousands of photographs of minerals and some I have tried to re-photograph over and over and never was satisfied with the results.

As you take more and more photos you may find some just don't behave.

Under a microscope there are a few that are notoriously hard, gold and azurite are but two that come immediately to mind. Some like dioptase are very hard to get the color right.

Mostly I am talking about mineral crystals.

So, to reiterate, yes, some minerals are hard to photograph. Time and thousands of photos should give you practice and a much better ability to get good photos.

There are no shortcuts.

In the end, have fun and don't get frustrated, most of us have been through the exactly the same thing.

Rolf

9th Jan 2015 17:16 UTCOlivier Langelier

Keith: the reason I'm so interested in this particular grain is that amongst the thousands of

grains I have observed in the last years this is the first one that gives me this much trouble

and it fuels my curiosity.

I wouldnt come here and ask something like that because I forgot to remove the cap on the

camera or turn on the light. I have genuine reasons to believe that the reason for this is an

optical property of the mineral. It's like it's transparent but at the same time it's not.

9th Jan 2015 18:42 UTCRonald J. Pellar Expert

If its a color difference that is concerning you, certain materials can change color under different lights and in some cases with different sensor responses. The characteristic is sometimes referred to as "metamerism". In your case it could be caused by the spectral response of the sensor in your Canon camera differing slightly from the spectral responses of the sensors in your microscope camera, i.e., the two camera will see the colors differently. It will take an object with unusual spectral reflectivity for this effect to show up and most objects (minerals) won't show this effect.

Hope this helps,

Ron

9th Jan 2015 19:13 UTCOlivier Langelier

That's a good point Ronald, but again the thing is it does it only with this mineral.

All others work just fine and show the same color.

Truth is I already have a good idea of what it is. It's tiny, yellowish, it's the only

such specimen I've ever found and an argument could be made that it does look

somewhat octahedral. One mineral fits this description perfectly and is also known

as notoriously difficult to photograph. I was curious to see if anybody would notice

and raise the possibility. I'm not saying it cause I don't want to jinx myself but you

all probably know what I'm talking about.

I shipped it to the lab.

9th Jan 2015 20:21 UTCReiner Mielke Expert

" you all probably know what I'm talking about." No what are you talking about?

9th Jan 2015 20:57 UTCOlivier Langelier

Well I compared another image of the grain with a picture of what it

could be and I can't help but notice the striking similarity. I do not

presume to know the exact origin of the rock fragment, for all I know

it's a glacial erratic. It would explain everything.

10th Jan 2015 00:14 UTCReiner Mielke Expert

Boy were we ever of the mark on that one. We should have known it was difficult to photograph because it was diamond LOL.

10th Jan 2015 00:23 UTCOlivier Langelier

That's not what I said. Let me ask you this Reiner, why are you so unpleasant?

A little bit of courtesy sure wouldn't kill ya

10th Jan 2015 01:41 UTCReiner Mielke Expert

Why are you always looking for an answer you want to hear rather than an answer?

10th Jan 2015 02:01 UTCOlivier Langelier

Well because I'm not sure duh! Why do you talk so much if you have nothing to contribute?

10th Jan 2015 02:07 UTCReiner Mielke Expert

Whatever.

10th Jan 2015 13:47 UTCHenry Barwood

Only my opinion, but it looks like you are trying to photograph in the direction of cleavage or parting planes in the mineral. This will confuse both the eye and the autofocus on cameras. If you are having difficulty getting an image that is in focus simply take a "stack" of images as you focus using small intervals from out of focus through focus and back to out of focus in the other direction. just select the best image from the stack.

10th Jan 2015 18:44 UTCDoug Daniels

What the heck - a few more questions/observations.

First, where is the beastie from?

Second, the first photo shows an overall reddish/shades of green matrix, almost (that is, almost) like an eclogite. But, the specimen is a bit dark, likely because of the white background influencing the exposure. A photo on either a black or (preferably) gray background would give a better indication of the color scheme that's happening.

Third, I can see a vague octahedral pattern in the inset photo on the first one. If the matrix is an eclogite (very maybe), the maybe (very maybe) that grain is a diamond. Except, I don't think that eclogite is a matrix for diamond, or if it is, it's darned rare.

But, if you've sent it off to a lab, then I guess we'll soon know what it is. Let us know the results...will be interesting any which way it goes (that is, we will have all learned something).

10th Jan 2015 19:01 UTCOlivier Langelier

Doug: In fact I read that some eclogite nodules have been found with incredibly high diamond grades,

even up to 20,000ct/t according to some sources.

The whole point of this topic was to see if people would come up with examples of minerals that are

difficult to photograph and otherwise fit what can be seen on my images. I spent hours on this grain

taking pictures from every angle possible with different lighting levels but the result is always the same.

11th Jan 2015 20:01 UTCJohn A. Jaszczak Expert

A few observations about diamonds:

They actually can be rather tricky to photograph due to their high index of refraction and adamantane luster. I was recently photographing a 1-cm diamond (var. carbonado) from Bangui Region, Central African Republic, and was frustrated in not being able to capture a faint translucency I could observe if I had the lights right. I was able to document striking photographic differences depending on if the sample was on a dark back ground or a light background, and with diffuse lighting or direct lighting (both with LED). Please see the examples here where the top image had a dark background and diffuse lighting, and the bottom image had

direct lighting and white background:

I also would like to comment that yes indeed, diamonds do occur in some eclogites- sometimes rather richly. Here is an

example from my collection- a 3-cm octahedron in a 4x3.5x1.5-mm eclogite nodule that contains at least 4 other smaller and broken diamonds. It is from Udachnaya mine, Sakha Republic, Russia.

Cheers

John

11th Jan 2015 20:23 UTCturtledove thrushe

John A. Jaszczak Wrote:

-------------------------------------------------------

> A few observations about diamonds:

>

> They actually can be rather tricky to photograph

> due to their high index of refraction and

> adamantane luster. I was recently photographing a

> 1-cm diamond (var. carbonado) from Bangui Region,

> Central African Republic, and was frustrated in

> not being able to capture a faint translucency I

> could observe if I had the lights right. I was

> able to document striking photographic differences

> depending on if the sample was on a dark back

> ground or a light background, and with diffuse

> lighting or direct lighting (both with LED).

> Please see the examples here where the top image

> had a dark background and diffuse lighting, and

> the bottom image had

> direct lighting and white background:

>

>

> I also would like to comment that yes indeed,

> diamonds do occur in some eclogites- sometimes

> rather richly. Here is an

> example from my collection- a 3-cm octahedron in a

> 4x3.5x1.5-cm eclogite nodule that contains at

> least 4 other smaller and broken diamonds. It is

> from Udachnaya mine, Sakha Republic, Russia.

>

>

> Cheers

> John

John I believe that the 3cm Octahedron is rather a 3mm Octahedron as I haven't seen any diamonds from that locality of that size.

11th Jan 2015 20:50 UTCOlivier Langelier

Very nice specimen John!

I don't think mine is an eclogite though. It is most likely a peridotite.

It comes from a yet undocumented source.

11th Jan 2015 21:38 UTCMichael Wood

Hi Olivier, I've thought all along that your whole specimen looked like eclogite, just a bit different-looking. Maybe it is eclogite that has been subject to a degree of retrograde metamorphism? I hope the test results prove diamond, that would be very cool indeed!

John, thanks for the carbonado photo's, they are very instructive. Love the diamond octahedron in eclogite from Udachnaya, but it's got to be 3mm, surely...

Cheers, Mike

11th Jan 2015 21:42 UTCOlivier Langelier

Thx Mike. It would be worth a lot to me, my pleasure is not in owning the best specimen

but rather specimen I found myself no matter how bad :-D

11th Jan 2015 22:30 UTCJohn A. Jaszczak Expert

Thanks for noting my error in the size of the diamond. Indeed, it is 3 mm, not 3 cm.

Cheers

John

11th Jan 2015 22:49 UTCKeith Compton 🌟 Manager

Olivier,

Perhaps if you try and scratch it with something very hard - perhaps sapphire etc, and if it does, then you will know it is not a diamond.

Cheers

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