Natural volcanic zeolite is a silicate mineral having a unique interconnecting lattice structure. It's honeycomb framework of consistent diameter interconnecting channels and pores coupled with negatively charged alumina and neutrally charged silica tetrahedra building produces an open three dimensional honeycomb framework that attracts liquids, odors & gases and traps them in its crystalline structure. Zeolites are commonly used in environmental cleanup because of their ability to absorb selected pollutants and lock them inside its structure.
Zeolite at Wikipedia
International Zeolites Association