'Muller's glass' definitions:

Definition of 'Muller's glass'

From: GCIDE

Hyalite \Hy"a*lite\, n. [Gr. "y`alos glass: cf. F. hyalite.] (Min.) A pellucid variety of opal in globules looking like colorless gum or resin; -- called also {M["u]ller's glass}. [1913 Webster]