I think that this tiny beauty is a Silvery Blue --
I've seen them around for years and never managed to photograph one. The topside of their wings is quite blue -- unfortunately, they flitter around very quickly and when they do alight, their wings are folded, showing the pretty silvery-blue underside.
Also, they stay close to the ground -- and it's not easy for me to get down to that level quickly. By the time I do, the fickle thing has moved on.