Saponite

Saponite is a naturally occurring 2:1 phyllosilicate clay of the smectite (montmorillonite) group. It is a magnesium-rich hydrated aluminum silicate and is present as a component of some commercial magnesium aluminum silicate clays. It occurs in soft, amorphous masses in the cavities of certain rocks.
Saponite occurs as a white to off-white, dull powder composed of fine-grained crystals of colloidal size. The material is greasy or soapy to the touch and swells on the addition of water.

Naturally occurring saponite is mined from deposits in various localities around the world.

Saponite is an example of smectite, a 2:l clay mineral. This 2:l layer has aluminum octahedral sheets sandwiched between two silicon tetrahedral sheets to make a unit cell. In saponite, all the octahedral holes are filled with magnesium ions and 15 to 20% of the tetrahedral holes are filled with aluminum ions. The rest of the holes are filled with silicon.

Saponite is a colloidal material present in various naturally occurring clays such as magnesium aluminum silicates and is therefore suitable for use in pharmaceutical formulation applications as an adsorbent, viscosity-increasing agent, suspending agent, or as an oil-in-water emulsifying agent.
Saponite, as a component of magnesium aluminium silicates, is useful as a formulation component in semisolid cosmetic and health care products.

Saponite is a natural clay mineral that is not acutely toxic; therefore, no toxicity values have been established. However, it may contain small amounts of crystalline silica in the form of quartz. Chronic exposure to crystalline silica can have adverse effects on the respiratory system. EU labeling states the material is not classified as dangerous.
Saponite dust can be irritating to the respiratory tract and eyes. Contact with this material may cause drying of the skin.

Saponite is a stable material and should be stored in a cool, dry place.

May generate heat in contact with hydrofluoric acid.

Reported in the EPA TSCA Inventory.