Crystallize

You harden your mana into an inanimate crystal-like object in your hand or on the ground in an unoccupied space that you can see within 5 feet of you. This object can be no larger than 2 feet on a side and weigh no more than 10 pounds, and its form must be that of a nonmagical object that you have seen. The object is visibly magical.

The object shatters after 1 hour or if it takes or deals any damage. You can only have 1 instance of this cantrip active at a time