[1] In his many contributions to scientific journals he described the granulite group, and dealt with pegmatites, variolites, eurites, the ophites of the Pyrenees,[2] the extinct volcanoes of Central France, gneisses, and crystalline schists.

[3] He wrote "Structures et classification des roches éruptives" (1889), but his more elaborate studies were carried out with Ferdinand André Fouqué.

[1] Together they wrote on the artificial production of feldspar, nepheline and other minerals, and also of meteorites, and produced "Minéralogie micrographique: roches éruptives françaises" (1879) and "Synthése des minéraux et des roches" (1882).

[3][4] Michel-Lévy pioneered the use of birefringence to identify minerals in thin section with a petrographic microscope.

He also created classification schemes for igneous rocks which accounted for their mineralogy, texture, and composition, and showed that igneous rocks of different mineralogies could be formed from the same chemical composition, with different conditions of crystallization.