Emerald Shard

Emerald Shards are objects that appear in the anime series Sonic X. They are the fragments of the Master Emerald created when the gem has been forced into shattering.

Description
As fragments of the Master Emerald, the Emerald Shard are green emerald pieces in various shapes and sizes, each retaining a fraction of their gestalt form's power. When formed, most of the Emerald Shards are spread across a wide region, making the task of gathering them rather painstaking. As the Master Emerald's guardian, Knuckles the Echidna is shown to have limited control over the Emerald Shards which lets him levitate them through midair.

Should the Emerald Shards be gathered in one place, they will reform into the Master Emerald, returning it to its pristine state. However, if the Master Emerald loses its power when its shatters, the Emerald Shards are rendered completely inert, meaning they cannot reform the Master Emerald. When reduced to such a state, the Emerald Shards can heal themselves naturally, although the process can take years.

Chaos Saga
When the Master Emerald was shattered by Dr. Eggman to release Chaos, its Emerald Shards were scatter far and wide, causing Angel island to fall into the sea. As such, Knuckles began searching for the fragments across various areas, from Casinopolis (where a shard caused massive destruction) to the Mystic Ruins. Whenever Knuckles found a fragment, it would show him a vision of Tikal and Chaos' past. After bringing most of the shards back together, the partially-restored Master Emerald showed the remaining fragments were on the Egg Carrier to Knuckles. Journeying to the Egg Carrier, Knuckles recovered the last Emerald Shards and brought them back to Angel Island to reunite them with the Master Emerald.

Metarex Saga
During the battle with Final Mova, the Master Emerald shattered into several powerless Emerald Shards after being pushed too far to fire an extra powerful blast with the Sonic Power Cannon. This time however, the shards stayed in the same place. After the battle, Knuckles brought the Emerald Shards back to Angel Island where they could heal naturally, although it would take some time.