The term used to describe hair that has not been chemically altered is:

Virgin hair is the term used to describe hair that has not undergone any chemical treatments or alterations. This type of hair retains its natural characteristics, texture, and color, making it ideal for various hair services that require a healthy, unaltered base. Hair stylists and professionals often seek virgin hair because it responds better to coloring, styling, and treatments, as there have been no previous interventions that would compromise its integrity.

On the contrary, processed hair refers to hair that has been altered through chemical treatments such as dyeing, perming, or relaxing. Treated hair is another descriptor for hair that has undergone any form of chemical alteration, thereby losing its virgin status. Styled hair signifies the method in which hair has been arranged or groomed but does not inherently address whether the hair has been chemically treated or not. Therefore, virgin hair is the most accurate term for hair that remains in its natural, unaltered condition.