I have to disagree with jamesbibb that's not a common magical water faery egg I'm pretty sure its a druidic well stone. Faery eggs hatch after the spring appears and the larval form of the faery, a water nymph, emerges. Druidic well stones can be used a few times before their magical charge wears off~ the blue lights fade with use. You'd have to talk to the druids who made it to get it charged back up again but they would probably take it back if you showed them you had it. The water from such stones is said to have healing abilities and when used in a scrying bowl can show events of the future. Very difficult to make so who ever lost it is probably pretty upset.
