What it is
This is the reaction product of hectorite clay with stearalkonium chloride, producing an organoclay that swells in oils and nonpolar solvents. It builds viscosity and a gel structure in the oil phase, which helps suspend pigments and mineral UV filters and keeps them evenly dispersed. It is widely used in sunscreens and color cosmetics to prevent settling and to give a stable, controlled texture.
Safety & warnings
Stearalkonium hectorite is generally well tolerated as it functions as an inert structuring clay and stays on the skin surface. As an inorganic clay-based thickener it is not associated with comedogenicity and is not a recognized fragrance allergen.
Origin & sourcing
Semi-synthetic; made by treating the naturally occurring clay mineral hectorite with a quaternary ammonium compound (stearalkonium chloride) to make it oil-dispersible.
Questions everyone asks
Why is stearalkonium hectorite used in mineral sunscreens?
It thickens the oil phase and keeps mineral filters and pigments suspended evenly, which prevents settling and stabilizes the texture.
Is stearalkonium hectorite natural?
It starts from the natural clay hectorite but is chemically modified to disperse in oils, so it is best described as a semi-synthetic organoclay.