Scented Volcanic Rock Base

For making scented volcanic rock with 30% essential oil, both Reed Diffuser Base (Type 1) and Dipropylene Glycol can be used as a base to dissolve the essential oil.

However, Reed Diffuser Base (Type 1) is specifically formulated to help fragrances disperse and spread aroma effectively, which is ideal for scenting materials like volcanic rock used for diffusion. The recommended usage rate for this base is also around 70-75% base with 25-30% fragrance, fitting well with your plan to use 30% essential oil.

Dipropylene Glycol is also a good solvent for essential oils and acts as a fixative, helping the scent last longer by slowing down evaporation. While it will work, the Reed Diffuser Base (Type 1) is designed more specifically for the purpose of aroma diffusion from a medium.

Therefore, for creating scented volcanic rock intended for aroma diffusion, Reed Diffuser Base (Type 1) would be the more suitable choice.