Patty, my brother was a geology major, and I spent two years working as a Geology professor's lab assistant. We were both mountain climbers, and we picked up rocks along the way. If you find it on the way up you can't leave it hoping you'll find it on the way back down because you'll never see it again, so several rocks went up and back.

While seated on the summit of Glacier Peak (in the North Cascades) I randomly picked up a smallish piece of pumice and it rattled around in the top flap pocket of my day pack for ages before I set it aside at home. Maybe an inch across, it was quite airy and had some tiny black crystals - I think a hornblend. Later I happened to be talking to a climbing friend who described a display of the rocks he'd picked up on each climb, but he'd neglected to get one on Glacier Peak. He was considering climbing it again to get a rock so was thrilled when I offered the little piece I had (we were both in the climb that day.) I later saw the display and it was lovely.

Dorothy, good luck with getting Robin to organize his stuff.