They do not look like any preparation artifact I have ever seen (and I have seen many!), which might be supporting evidence to interpret them as PDFs....

Thank you Marlina for your insight :D

Hi Houssam, after my opinion and experiance looks like PDF´s. It seems to me that the sharp closely spaced lines in background are the PDF´s and the lines in the foreground are artificial grooves just juxtaposed on them and having their direction. You can observe the terminations of the later just in the middle of grains with small holes. The are wider and with the haloes (especially the photograph 5 from the top. I recommend You strongly to do either the TEM microscopy or high resolution electron microscopy of the broken surface of grains where you could see their sharpness and spacing which is generally less than 1 micrometer (http://www.geology.cz/bulletin/fulltext/03langenhorstfinal.pdf). I attach example of PDF´s picture from the high resolution electron microscopy

Thank you Petr for taking the time to help me out. I really appreciate it. I will follow your advice.

What are the minerals - quartz?  I've been looking at shocked zircons for a few years, and some of these features do look very much like PDFs, especially the photos #5 onwards, with the closely spaced parallel lines that look slightly defocused (as they seem to go progress deeper into the grains).  Others (e.g., photo # 7, top left) seem to be surface scratches, probably from polishing.  I tend to call them "planar features/PFs" unless you have identified the crystallographic planes associated with shock metamorphism, and only then do I call them PDFs.  Good quality SEM or TEM imaging will certainly help, on both broken and original surfaces.  Universal stages were commonly used to identify the crystallographic planes of PDFs, but Electron Back-Scattered Detector imaging (EBSD) is also being used now.  These look like good candidates, good luck.

Nothing to add to the previous collegues. I do feel you are observing PDFs due to shock in quartz.

Andrew Glikson at the Australian National University has looked at many PDF's and may be able to help.

Hi Houssam,

I have another opinion. At the first quick look, I would say that your images could contain some PDF, I cannot exclude this. But no one of your 10 Images show a clear, good developed PDF!

#1) not clear, some waves or ???

#2) fullgrains , from rim to rim is penetrate with PDF? Unusual, I would say.

#3) nothing, a few scrates

#4) nothing, some latts and curves

#5) parallel orientations in both two grains, unusual

#6) full grain with straition or inclusions, no other orientation vivible, also unusual

#7) maybe the best of your grains for containing PDF, but too bad Quality.

#8) the half Images Show the same striation, nothing.

#9 and 10) two/ three grains witzh the same orientation, no way.

I think you have two problems. First, you need better pictures. I´m convinced that the University have a set of microscope with a good camera! And the setting of your microscope is obviously not proper adjust. I have the impression that something is wrong, maybe the position of the aperture-lense. The second thing is that  I have no idea what kind of matrix you have. It seems like recrystallized glass or so. Perhaps the PDF are overprinted by high temperature (e.g. toasted) and this could be the reason for the poor preservation.

That´s from me,

good luck, Ulli.

Based on these optical images one cannot conclude if these are PDF's or Deformation lamellae or microscope/preparations artifacts.

As suggested before I recommend you look at these samples with SEM in CL, or BSE camera mode. Only then can you do some proper measurements of spacing and thickness. In my master thesis I looked at different shocked quartz grains and measured at spacing and thickness. If your features show similar characteristics I think you can conclude that you are looking at PDF's.

Here's a link to my msc thesis: Thesis A comparison between deformation lamellae and planar deforma...