The most common essential oils, including lavender, peppermint, and eucalyptus are extracted through the process of distillation. This requires the raw plant material to be into an alembic over water. An alembic is a type of distillation apparatus. The raw plant material may include any and/or all of following parts: the flowers, leaves, wood, bark, roots, seeds, or peel of the original ingredient. In the alembic, the steam, which is created as the water heats, passes through the plant material. This leads to the vaporization of the volatile compounds. The vapors then flow through a coil, where they condense back to liquid. This liquid is then collected, packaged and sold.