Sorby had an interest in geology and was involved in the Geological and Polytechnic Society between 1845 and 1846. He subsequently dealt with the
physical geography of former
geological periods, with the wave-structure in certain stratified rocks, and the origin of
slaty cleavage. Sorby began to produce thin slices of hard rocks based on the methods used in zoology that he had learned from professor
William Crawford Williamson. He also began to use polarized light to examine the thin transparent sections of rocks. He took up the study of rocks and minerals under the
microscope, and published an important memoir, "On the Microscopical Structure of Crystals", in 1858 (
Quart. Journ. Geol. Soc.). He then introduced spectrographic analysis techniques. In England, he was one of the pioneers in
petrography; he was awarded the
Wollaston medal by the
Geological Society of London in 1869, and became its president. In his presidential addresses, Sorby gave the results of original research on the structure and origin of
limestones and of non-calcareous
stratified rocks (1879–1880). In the mid-
Victorian years, Sorby was also the first to study the
cleavage of
slates using a microscope. In the frame of an ardent debate on the origin and mechanism of the slatey cleavage with the
Irish physicist
John Tyndall, who was also a pioneering mountain climber (Tyndall's name is also associated with the "
Golden age of alpinism") and visited the
Alps mountains in 1856 for scientific reasons, Sorby devised a quote now famous: :
Mountains must indeed be examined with the microscope. Sorby was one of the first to understand the role and the importance of microscopic processes to explain
material deformation and large scale phenomena such as
rock cleavage and
rock folding caused by
tectonic uplift and
orogeny. He studied the microscopical structure of
meteorites. In the summer of 1876 at South Kensington, he gave a lecture to science teachers on microscopes. == Metallography ==