Leaves of some varieties out of about 25 varieties of plants bearing the generic name “mentha” form the raw material of menthol. (For example, the leaves of a species named Mentha Arvensis shown in the accompanying photograph). Mentha oil is extracted from the leaves of these plants and crystallized. The crystal form is known as menthol (chemical formula: C₁₀H₂O). India is a leading producer of mentha and menthol, and nearly 70% of the total production is exported.