Rough Diamonds

micro_pix · Post by **micro_pix** » Wed May 20, 2020 10:53 am

I was inspired by Linden's colourful diamond photos so I found some 1mm rough diamond on eBay and tried some different lighting combinations, mostly reflected lighting.

Surface detail from the previous photo.

Stereo pair

rjlittlefield · Post by **rjlittlefield** » Wed May 20, 2020 11:11 am

Lovely images! The lighting is exquisite for showing surface texture without blowing the highlights.

The stereo works OK for me, but it seems notably less sharp than any of your others.

The stereo is also smaller, both in pixel count and file length, only 694 pixels wide and 76 KB.

I am curious, what prompted these choices?

--Rik

micro_pix · Post by **micro_pix** » Wed May 20, 2020 11:24 am

Thanks Rik. I messed up somewhere with the stereo image size, I’ll see if I can recover a larger one.

David

rjlittlefield · Post by **rjlittlefield** » Wed May 20, 2020 12:24 pm

Great!

While you're at it, consider adding some sharpening.

My experience is that stereo images are generally improved by a level of sharpening that would be considered too much in a single image.

As it appears right now, the stereo here seems to have gone the other direction.

--Rik

micro_pix · Post by **micro_pix** » Wed May 20, 2020 12:39 pm

I've re-done the stereo (it was my first go). I normally stack in full size tiff but I exported to Zerene in down sized .jpg for the stereo and put 1024 for the long edge (forgetting that the single image was portrait) so ended up with a 600 wide stereo image - after cropping to landscape. All fixed now and sharpened.

David

Linden.g · Post by **Linden.g** » Wed May 20, 2020 1:31 pm

Those are lovely David. I really like the detail showing the "trigons" and surface growth plates.

Ken Ramos · Post by **Ken Ramos** » Wed May 20, 2020 2:09 pm

Beautiful photos

The fifth one reminds me of some long lost math problem of yester-year having been scratched out on parchment.

rjlittlefield · Post by **rjlittlefield** » Wed May 20, 2020 2:18 pm

micro_pix wrote:I've re-done the stereo (it was my first go).

Lovely!

As usually happens, I get a lot more from stereo. With a single image I see, with a stereo pair I understand.

--Rik

micro_pix · Post by **micro_pix** » Thu May 21, 2020 4:28 am

Thanks for the comments. These tiny rough diamonds are fascinating subjects!

Here's another one lit to show the surface texture. I know very little about minerals but I suspect this has an accretion of something on the surface; while the shape and structure is diamond like, the surface "lava-like" texture (and what looks like thin film interference patterns) is possibly a different compound/mineral. This is probably why the diamond testers don't really work on rough diamonds.

Dave

-and another go at stereo

Linden.g · Post by **Linden.g** » Thu May 21, 2020 6:48 am

Love the interference rings

micro_pix · Post by **micro_pix** » Thu May 21, 2020 9:10 am

Small rough diamonds showing two distinct auto-fluorescence colours under UV excitation.

WalterD · Post by **WalterD** » Fri May 22, 2020 10:29 pm

Beautiful set, David.

I like the subtle rainbow of colors in the 2nd picture.
The autofluorescence in the last one results in a surprising different picture.

Charles Krebs · Post by **Charles Krebs** » Sat May 23, 2020 2:23 pm

Nicely photographed! Fascinating subject.

JW · Post by JW » Sat May 23, 2020 4:03 pm

Welcome to the world of mineral photography! Almost all natural diamonds, and natural crystals in general, show growth features on what may nominally appear to be smooth surfaces - it is up to us macrophotographers to show the wonder of these types of crystal imperfections. Diamond testers only work on smooth surfaces such as found on cut gemstones. Also, I am guessing the "violet" fluorescent response may just be a reflection from the visible violet emissions typical of UV lamps, as most diamonds are either non-fluorescent or fluorescent in the yellow-tan-white range. I stand corrected, diamonds are likely to fluoresce in many colors, including blue.

Regardless, an excellent set of images of a fascinating subject. (I can't see stereo images due to having only 1.2 eyes)

micro_pix · Post by **micro_pix** » Sat May 23, 2020 5:07 pm

.
Thanks for the comments.

JW wrote: I am guessing the "violet" fluorescent response may just be a reflection from the visible violet emissions typical of UV lamps, as most diamonds are either non-fluorescent or fluorescent in the yellow-tan-white range.[/size] I stand corrected, diamonds are likely to fluoresce in many colors, including blue.

Thanks JW.

This was on a fluorescence microscope set-up using a mecury lamp with an UV exciter filter that cuts off at just under 400 nanometers and I had a barrier filter of 460 nanometers so it's definitely true fluorescence. There are probably about a thousand 1mm diamonds in the pack I bought and something like 15-20% fluoresced when I shone a UV torch on them. I selected a handful of the brighter fluorescing ones and put them under the scope.

I did read that the range of colours is quite wide but I also read that it's related to the elements/impurities in the diamond and so related to their origin to some extent, I don't know that that the tiny diamonds in this pack came from the same place but I only found ones that were fluorescing blue or green.

There's a nice picture that someone has put on Flikr which shows some of the range of colours https://flic.kr/p/2hgPnWb

Dave