maceraln.

1935 M. C. Stopes in Fuel in Sci. & Pract. 14 11/1 To..construct an acceptable petrological classification, therefore, a prime need became obvious, viz., a word to cover all petrological units seen in microscopic sections of coals, as distinct from the visible units seen in hand specimens... I now propose the new word ‘Maceral’ (from the Latin, macerare, to macerate)... The word ‘macerals’ will, I hope, be accepted as a pleasantly sounding parallel to the word ‘minerals’, conveying the suggestions of the fundamental difference between them.

1935 M. C. Stopes in Fuel in Sci. & Pract. 14 11/1 The concept behind the word ‘macerals’ is that the complex of biological units represented by a forest tree which crashed into a watery swamp and there partly decomposed and was macerated in the process of coal formation, did not in that process become uniform throughout but still retains delimited regions optically differing under the microscope, which may or may not have different chemical formulae and properties. These organic units, composing the coal mass I propose to call macerals, and they are the descriptive equivalent of the inorganic units composing most rock masses and universally called minerals.

1966 McGraw-Hill Encycl. Sci. & Technol. (rev. ed.) III. 232/2 As a means of simplification, three varieties, or maceral groups, have been set up: vitrinite..resinite..and inertinite.

1970 Nature 11 July 194/2 The petrographic components (macerals) of coals possess different stability ranges.

1987 P. J. McCabe in A. C. Scott Coal & Coal-bearing Strata 53 Lithotypes of coal are normally defined on both the maceral composition and the overall texture of the coal.