Source: Tasha's Cauldron of Everything

Wondrous item, uncommon (requires attunement by a sorcerer)

This warm crystal glints with the sunset colors of the Feywild sky and evokes whispers of emotional memory. As an action, you can attach the shard to a Tiny object (such as a weapon or a piece of jewelry) or detach it. It falls off if your attunement to it ends. You can use the shard as a spellcasting focus while you hold or wear it.

When you use a Metamagic option on a spell while you are holding or wearing the shard, you can roll on the Wild Magic Surge table in the Player's Handbook. If the result is a spell, it is too wild to be affected by your Metamagic, and if it normally requires concentration, it doesn't require concentration in this case; the spell lasts for its full duration.

If you don't have the Wild Magic Sorcerous Origin, once this property is used to roll on the Wild Magic Surge table, it can't be used again until the next dawn.