Min. [mod. f. Gr. ἀπό off + φύλλον leaf + -ITE; ‘so named by Haüy, 1805, in allusion to its tendency to exfoliate under the blow-pipe’ (Dana).] A zeolitic mineral, a hydrated silicate of lime and potash, with a trace of fluorine; occurring in glassy square prisms or octahedrons, or laminated masses, with a pearly luster; widely distributed in nature, and produced artificially.
1810. Edin. Rev., XVII. 119. The sparry lustre which characterizes apophyllite.
1878. Lawrence, Cotta’s Rocks Class., 26. Apophyllite is found in the geodic cavities of volcanic rocks.
