＇＇Hard＇＇ carbon-based Pennsylvania anthracite was deformed in the steady-state at high temperatures and pressures in a series of coaxial and simple shear experiments designed to constrain the role of shear strain and strain energy in the graphitization process. Graphitization did not occur in coaxially deformed anthracite. Nonetheless, dramatic molecular ordering occurs at Tb 700 degrees C, with average bireflectance values (%) increasing from 1.68 at 700 degrees C to 6.36 at 900 degrees C. R(o min) is lowest and bireflectance is highest in zones of high strain (e.g., kink bands) at all temperatures. In anthracite samples deformed in simple shear over the 600 degrees-900 degrees C range at 1.0 GPa, average R(o max) (%) values increase up to 11.9, whereas average bireflectance (%) values increase up to 10.7. Bireflectance increases with increasing shear strain and locally exceeds 12.5%. Graphitization occurs in several anthracite samples deformed in simple shear at 900 degrees C. X-ray diffraction and transmission electron microscopy confirms the presence of graphite with d(002)=0.3363 nm. These data strongly suggest that shear strain is the dominant factor responsible for the natural transformation of anthracite to graphite at temperatures far below the 1600 degrees C required for graphitization of other hard carbons in earlier hydrostatic heating experiments at 0.5 GPa pressure.