Dear Dr. Katleen Deckers,

I mainly deal with microscopies measurements on metallic materials but I think that you could try to soak your sample in alcohol and freezing it in liquid nitrogen, then try to get a clean section that way. Another way could be to mount the sample in a resin and then use a microtome to obtain a sections that you could then optimize with light abrasion methods....

I suggest to have a look at the following interesting paper:

-The principles, procedures and pitfalls in identifying archaeological and historical wood samples

Caroline R. Cartwright

Ann Bot., 116(1): 1–13 (2015)

Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4479747/

Best regards, Pierluigi Traverso

Thanks a lot. I think I will try the impregnation and microtome.

Dear Dr. Katleen Deckers,

May I recommend the use of steel-bonded diamond grinding discs with grain sizes 600 mesh and 1200 mesh. These discs can be used both dry and wet. These discs are commercially available for 15 to 20 euros each.

The photo attached shows the surface of a disc with a diameter of 15 cm. The micrograph in reflected light of the surface of a 1200 disc shows the individual steel-bonded diamond fragments, width of image 0.5 mm. These steel disks can be fixed with a magnetic base either on a firm, flat surface or on a rotating base.

The advantage of diamond discs compared to sandpaper or abrasive cloth is clearly that no abrasives come off the steel discs and can clog the pores of the charcoal. You don't need any impregnation agents.

May I also recommend our paper "Preparation methods in Mineralogy & Geology", see PDF attached.

Good luck!

Kind regards,

Guenter Grundmann