This paper explores the philosophical and practical implications of the natural versus synthetic distinction in chemistry. I consider several interpretations of the term natural as pertaining to substances, and conclude that at its core, naturalness is best understood as a statement about material origin. The analysis reveals that calling a chemical substance natural risks committing a category mistake. The descriptor can only be coherently applied to samples of a chemical substance, not to a chemical substance as a set. Even in the case of samples, the utility of the term is limited. Care must be taken to avoid unwarranted implications.