We routinely work on a ca. 1 cm-thick slab cut along the axial zone of stalagmites. This slab is polished and cut longitudinally. One half is used for petrography and dating, while the other half is used for stable isotope and trace-element analyses.
For petrographic work we use standard thin sections and a Nikon Eclipse polarizing microscope equipped with a uv- and blue-light source for epifluorescence.
We also have a Keyence VHX-5000 digital microscope for 3D-viewing of objects of a wide range of scales.