Sapphire Star (Wario: Master of Disguise)
From the Super Mario Wiki
Sapphire Stars are objects found in Wario: Master of Disguise. They are blue boxes with shining star icons on them which appear frequently throughout the game. Shooting them with Cosmic Wario's lasers causes them to drop coins and gems. Goodstyle advises Wario to vary the pace of his shots in order to make them drop more coins and gems. After being shot once, the star icon will stop shining after a few seconds pass or it is shot enough times, signifying that no more coins or gems can be obtained from it.