Crystal Clusters are large crystals that are scattered througout every stage in Freedom Planet. Each Cluster hold a total of 7 Crystal Shards, which can be obtained simply by breaking it. They can even be picked up and thrown by Milla. Crystal Clusters can also be broken by Enemy attacks.
In Freedom Planet 2, Crystal Clusters will also be on walls and ceilings. Also, the Crystal Shards that come out of a broken Cluster will automatically be drawn in to the player character.