The Collaborative International Dictionary of English v.0.48:

Glossiness \Gloss"i*ness\, n. [From Glossy.]
   The condition or quality of being glossy; the luster or
   brightness of a smooth surface. --Boyle.
   [1913 Webster]

WordNet (r) 3.0 (2006):

glossiness
    n 1: the property of being smooth and shiny [syn: polish,
         gloss, glossiness, burnish]