At left is a stereo-zoom 10x to 70x Bausch & Lomb microscope mounted to a B&L Boom Stand that can easily examine the top and all sides of a 1+ foot cube size rock.

At right is a stereo-zoom 8x to 40x Bausch & Lomb microscope for handling glass slides to fist size rocks.

At left is a 35x to 1200x Olympus microscope used primarily for samples on glass slides.
At right is a 25x to 1000x Bausch & Lomb microscope used primarily for sawed rock and metal slabs.