Crystal (Super Mario Galaxy)
From the Super Mario Wiki
A Crystal is an object found in Super Mario Galaxy and its sequel, Super Mario Galaxy 2. They are quartz-like objects that can be found in multiple areas of the levels in the two games, and typically hold objects or items.
Inside them are items such as coins, 1-Up Mushrooms, and the occasional Launch Star or Life Mushroom. There are also octahedron crystals which contain only power-ups. Most of these crystals contain Star Bits; however, some may even contain Lumas or Toads, who help the player out once they are freed. Crystals sometimes contain enemies, namely Goombas. The quantity of Star Bits obtained averages from three to ten, and most of the Crystals found throughout the game contain four to six.
Crystals have fairly weak structures and can be shattered in both Super Mario Galaxy games by a variety of attacks, including Mario's standard Spin, Fireballs, Green Shells and Red Shells, and Rock Mario's boulder attack.
There are also large, rare Crystals that contain Power Stars. Large Crystals require two spins to be shattered.
Super Mario series
Super Mario Galaxy
Super Mario Galaxy 2
Crystals reappear in Super Mario Galaxy 2, retaining their appearance and behavior from the previous game. In the opening of this game, they are seen dropping from the sky during Bowser's attack on the Mushroom Kingdom. Anything hit by the crystal bits is trapped in a Crystal, unable to move.
Mario Party 10
In Mario Party 10, three Crystal-like recipients appear on different sides of the Rosalina Board, containing Star Bits. When the player lands on an Event Space, the Crystal associated with it opens and empties itself of the Star Bits, commencing a short minigame where the player has to collect as many Star Bits as possible within a time limit.