Min. [Named, 1820, after Dr. Thomas Thomson (1773–1852), professor of chemistry at Glasgow: see -ITE1.] Hydrous silicate of aluminium, calcium, and sodium, found often in fibrous radiated masses, white to reddish-brown in color; = COMPTONITE.
1820. H. J. Brooke, in Ann. Philos., Sept., 193. I shall call the Auvergne variety, Mesotype; that from Iceland and Ferro, Needlestone; and that from Dumbarton, Thomsonite, after the editor of this journal [Dr. T. Thomson].
1843. Portlock, Geol., 215. Thomsonite … is rarely met in Irish trap.
1869. Phillips, Vesuv., x. 294. Thomsonite, or Comptonite [occurs] in ejected blocks of gray lava.
