What it is
This is a manufactured borosilicate glass containing calcium and aluminum, typically produced as thin, smooth flakes that may be coated with metal oxides to create soft luminosity or color travel. In cosmetics it acts as a substrate for pearlescent and effect pigments and lends a smooth, slippery feel. In tinted and tone-up sunscreens it helps blur the surface and give an even, light-diffusing finish.
Safety & warnings
This glass is chemically inert and stays on the skin surface, so it is generally well tolerated with low irritation potential. It is not a fragrance allergen and is not an oil, so comedogenicity is not a typical concern.
Origin & sourcing
Synthetic. It is made by melting and forming silica with boron, calcium, and aluminum oxides into a glass, then milling it into flakes.
Questions everyone asks
Is this real glass in my sunscreen?
Yes, it is a cosmetic-grade borosilicate glass milled into tiny smooth flakes; it is inert and sits on the skin surface.
What does it add to a tinted sunscreen?
It carries effect pigments and helps create a smooth, light-diffusing, even-looking finish.