Lustrous, reflective (5)
I believe the answer is:
shiny
I believe this clue is a double definition.
'lustrous' is the first definition.
(I know that lustrous can be written as shiny)
'reflective' is the second definition.
(having a reflective surface)
(Other definitions for shiny that I've seen before include "Polished, reflective" , "Lustrous, glossy" , "Gleaming" , "Polished and reflecting light" , "Smooth and polished" .)