Yes, that's a great idea (relating the slides with rocks and minerals). I was thinking last night that the paper fibers looked like you were seeing them under a microscope, they are blown up so much.
The digital photos I took of the projected images turned out great, I'll try to get them online somehow tomorrow. The ones of the slides themselves pose more of a problem. They are so small they get blurry when I crop and enlarge them in Photoshop.
We have a school website, I keep meaning to ask for a page, this would be a good time I suppose.