Emily Dickinson Lexicon

A-POPH'YL-LITE, n. [Gr. απο, from, and φυλλον, a leaf; so called because of its tendency to exfoliate.]

A mineral occurring in laminated masses, or in regular prismatic crystals, having a strong and peculiar pearly luster. Its structure is foliated, and when a fragment is forcibly rubbed against a hard body, it separates into thin lamins, like selenite. It exfoliates also before the flame of a lamp. From its peculiar luster, it is sometimes called by the harsh name, ichthyophthalmite, fish-eye stone. – Cleaveland.