From Butter London's fall collection—this is 3 Free Nail Lacquer in Lovely Jubbly. It looks like festively pulverized tinsel, more confetti-dust than glitter, and we're digging it.
P.S. If you're wondering what "lovely jubbly" means, here's a definition courtesy of the BBC:
"It's a jocular exclamation. It means excellent, brilliant, great. It's the sort of thing you'd say when you got some good news or had a stroke of luck, [like] 'Ah, lovely jubbly.'"