The adjective sparkly is useful for describing an object that glints with light, like a disco ball, or a person whose personality is equally bright and bubbly.
A little girl's glittery shoes are sparkly, and so is sunlight flashing on the surface of a lake. When people are described as sparkly, it's usually because they are vivacious and enthusiastic, the life of the party. The word sparkly was first used in the 1920s, from sparkle, which in turn comes from spark. The origin isn't known for sure, but it may be rooted in the Old Norse word sparkr, "sprightly."