透长石

Glassy \Glass"y\, a.
1. Made of glass; vitreous; as, a glassy substance. --Bacon.

2. Resembling glass in its properties, as in smoothness,
brittleness, or transparency; as, a glassy stream; a
glassy surface; the glassy deep.

3. Dull; wanting life or fire; lackluster; -- said of the
eyes. ``In his glassy eye.'' --Byron.

{Glassy feldspar} (Min.), a variety of orthoclase; sanidine.

Sanidine \San"i*dine\, n. [Gr. ?. ?, a board. So called in
allusion to the tabular crystals.] (Min.)
A variety of orthoclase feldspar common in certain eruptive
rocks, as trachyte; -- called also {glassy feldspar}.