durain

plural durains

1. countableuncountableA type of coal.

   Bands are visible in the coal from this seam, and there are more durain and fusain parts of coal than vitrain and clairain.

   1968 September, Ashwini Kumar Singh, “The Source of Coal Samples”, in Desorption Studies of Gases from Coal, Edmonton, Alta.: University of Alberta, →OCLC, “Experimental Studies” section, page 27

   2 more examples

   The comparative absence of durain in many American coals caused some confusion in early attempts to correlate the English and American systems of nomenclature, since the duller portions of the American coals were at first compared with the English durains, whereas they should have been compared with the duller portions of clarains.

   1954, Wilfrid Francis, “The Coal Series—Terminology, Structure and Petrology”, in Coal: Its Formation and Composition, London: Edward Arnold (Publishers) Ltd., →OCLC, page 262

   The more durain-rich eastern Kentucky coal, with a higher proportion of inertinite- and liptinite-rich microlithotypes within the relatively low-HGI dull lithotypes, did not show as great a shift toward inertinite concentration in the fines as did the brighter western Kentucky coal.

   2008, Joan S. Esterle, “Breakage During Mining”, in Isabel Suárez-Ruiz, John C. Crelling, editors, Applied Coal Petrology: The Role of Petrology in Coal Utilization, Burlington, Mass.; San Diego, Calif.; London: Academic Press, →ISBN, chapter 3 (Mining and Beneficiation), page 70