Experiments in chemistry involving use of stereo microscope? I recently got a decent stereo microscope. Besides using the scope to teach my children, I have been thinking of picking up something new to learn myself. I have been interested about chemistry for a long time but never studied it after upper secondary school. I was thinking would there be some experiments that would allow me to learn more microscopy and chemistry at the same time? I have ~10  years of experience in machine vision, signal processing, neuroscience, programming etc., so research-grade problems are welcome too.
For starters, it might be fun to grow different kinds of crystals in shallow dishes and watch them grow in real time under a microscope. Either a low melting solid, melted and resolidified, or growing from a saturated solution. Also, looking at how a metal surface is etched by acid using a microscope would be fascinating.