[f. L. vermicul-ārī (see VERMICULATE v.) + -ITE1.]
1. Min. ‘Hydrous silicate of aluminium, iron, and magnesium, occurring in small foliated scales’ (Chester).
1824. T. H. Webb, in Amer. Jrnl. Sci. & Arts, VII. 55. If subjected to the flame of a blowpipe,… it expands and shoots out into a variety of fanciful forms, resembling most generally small worms.… If this proves to be a new variety … I term it Vermiculite (worm breeder).
1862. Dana, Man. Min., 149. Vermiculite … looks and feels like steatite; but when heated before the blowpipe, worm-like projections shoot out, owing to a separation of the thin leaves composing the grains.
1888. Rutley, Rock-forming Min. 199. Vermiculite and Jeffreysite are considered to be altered varieties of phlogopite.
b. pl. (See quot.)
1875. Ure’s Dict. Arts (ed. 7), III. 1074. Vermiculites, a group of minerals resembling the chlorites, remarkable for their exfoliation before the blowpipe.
2. Geol. ‘A short worm-track seen on the surface of many flagstones’ (1884 Imp. Dict.).
