Crystal Shards are important collectibles in Kirby 64: The Crystal Shards. They are pieces of the Crystal, an artifact of Ripple Star. Ribbon flies off with the Crystal after the Dark Matter invasion of Ripple Star, but three separate Dark Matter entities gave chase and shattered it into 74 pieces strewn across planets around Pop Star. It is then up to Kirby, Ribbon, Waddle Dee, Adeleine, and King Dedede to collect every shard.
The Shards are iridescent and radiate light. When they are brought close to each other, they combine into a larger whole.
Should all the Crystal Shards be collected, the Crystal purges Dark Matter from Queen Fairy, and 0²'s boss fight becomes available after Dark Star forms near Ripple Star from the Dark Matter. Defeating 0² gives the good canon ending of Kirby 64: The Crystal Shards, where Kirby, Waddle Dee, Adeleine, and King Dedede are presented with medals resembling the Shards themselves. It is not known whether these are replicas or the actual Shards, as the Crystal does not fully function unless it is whole.
Crystal Shards can be found just lying around in each stage, or in the possession of a boss or mid-boss. Occasionally they are hidden behind colored barriers, which can only be broken by hitting them with the Copy Ability/Copy Abilities of the corresponding color(s). For example, a green and red block would correspond to Cutter and Burning, respectively, so Kirby must break it with Sword of Fire.