vitreous
vit.re.ous \'vi-tre--*s\ aj [L vitreus, fr. vitrum glass - more at WOAD] 1:
of, relating to, derived from, or consisting of glass 2: resembling glass
(as in color, composition, brittleness, or luster) : GLASSY {~ rocks} 3:
of, relating to, or constituting the vitreous humor - vit.re.ous.ly av
Webster's English Dictionary