Metamict is a word used to describe a mineral that has lost its crystal structure due to natural radiation. Synonyms for this word include amorphous, disordered, non-crystalline, and structureless. Amorphous refers to materials that lack a definite shape or structure, while disordered describes objects that lack organization or arrangement. Non-crystalline means that a material is not composed of ordered, repeated geometric patterns. Structureless simply means lacking a discernible structure. All of these words can be used in place of "metamict" to describe minerals that have been affected by natural radiation. As a result of this radiation, the crystal structure of the mineral is lost, and it becomes amorphous, disordered, non-crystalline, or structureless.