Maceral

Part of speech: noun

Definitions

1. A microscopically identifiable organic constituent of coal, distinguished by its shape, colour and reflectance under a microscope
2. Any of the tiny, visually distinct organic particles that make up coal and are studied in coal petrology
3. A minute plant-derived component of coal, classified by its appearance when viewed in polished section under light

Etymology: Marie Stopes, better known today for her work on birth control, coined this word in 1935 while writing about coal. In a paper on the petrology of banded bituminous coal, she proposed "maceral" as a term that would sit alongside "mineral" as a matching formation, and she chose it deliberately from the Latin "macerare", meaning to macerate, or soak and soften. The reasoning was that coal is made of macerated plant fragments. Stopes argued that whatever the original nature of the coals, they all consist of the macerated remains of vegetation accumulated under water, so a word built on "macerate" fitted the material well. The English suffix "-al", as in "mineral", completes the form.