Vickers microhardness of telovitrinite and pseudovitrinite from high volatile bituminous Kentucky coals

Vickers microhardness was determined on telovitrinite and pseudovitrinite from a series of 49 high volatile bituminous Pennsylvanian-age coals from Eastern Kentucky (40 samples), part of the Central Appalachian coalfield, and Western Kentucky (nine samples), part of the Illinois Basin. Pseudovitrinite consistently has a higher microhardness than telovitrinite, the difference being greater for Eastern Kentucky than for Western Kentucky coals. The Amos coal, a low-sulfur coal from Western Kentucky, has significantly lower values than both other Western Kentucky coals and Eastern Kentucky coals of similar vitrinite maximum reflectance. The difference between the Amos and other coals, and between coals from the two coalfields, may lie in differences in the depositional history. Further study of iso-rank collections would help to identify a causative factor.