(1826-1908) English geologist whose discovery 1863 of the crystalline nature of steel led to the study of metallography. Thin-slicing of hard minerals enabled him to study the constituent minerals microscopically in transmitted light. He later employed the same techniques in the study of iron and steel under stress.
Sorby was born near Sheffield, privately educated, and spent his life as an independent scientific researcher.
In addition to microscopic study, Sorby used a Nicol prism to distinguish the different component minerals by the effect they produced on polarized light.
Sorby also extrapolated from laboratory models and small-scale natural processes in the expectation of explaining vast events in geological history.
He published On the Microscopical Structure of Crystals 1858.