Glitter (7)
(Other definitions for glitz that I've seen before include "Showiness" , "Extravagant superficial display (colloq.)" , "Garishness" .)
'glitter' is the definition.
(I know that glitter can be written as sparkle)
This is all the clue.
(Other definitions for sparkle that I've seen before include "Vivacity; flash with light" , "dash" , "Glisten" , "Shine (wittily)" , "Coruscate" .)