MicrobeHunter.com Microscopy Forum

Hey guys, I know this forum isn't really geared toward mineralogy but I figured I would share!(please remove if it's now allowed)

This is a .03mm section of rock that I ground down by hand, the picture was taken by holding my phone carefully over the monocular.

One image is Plain Polarized Light, the other is Cross Polarized Light.

The mineral in the center is Biotite which is easily identified by it's mottled texture, color and holes in it which are created by the radioactive decay of zircon(trace elements).

Very nice how long did it take you to get the thin section by hand and how did you do it?

Roldorf,

My first thin section took about 5 hours before I broke the glass and had to start over again, this was probably my 10th thin section and it took about 2 hours.

First a rock is cut into a billet( approximately the size of the slide on the X/Y axis), afterwards it is trimmed on the Z axis to about .5mm thick.

From there a series of sanding grit (80,120, 600, 1000) are used to shave the rock down (there are machines for this but I have limited access to them)

The grit is placed in a couple drops of water on top of a pane of glass which has a layer of aluminum foil wrapped around it, the softness of the foil helps prevent thin/thick spots.

The slide is worked by hand against the grit/foil until it's at the correct thickness and checked frequently so that it's not overdone.

Thanks for the post! It brings back fond memories of optical mineralogy class.

Wow, home-rolled so to speak. None of my professors seemed interested in grinding their own--maybe with some experience it can be done more quickly, but at 2 hours a slide I'm happy to send them off to be done for 20 dollars. I need to track down my thin section box, I'd love to have another look at them.

Very cool post! We don't see a lot of this sort of thing on this forum, and that's precisely what makes it so especially interesting. I hope you (and anyone else who has them) will post more thin section pics, and perhaps give a few words on them for context. I love it!