What it is
Quartz is crystalline silicon dioxide, one of the most common minerals in the earth's crust, milled to a fine powder for cosmetic use. In sunscreens, primers, and tone-up products it can function as a bulking and texture agent and can contribute to a soft-focus or mattifying finish. It is used as a formulation aid rather than as a UV filter.
Safety & warnings
As a finished topical ingredient in cosmetics it is used in particulate form and is generally regarded as well tolerated on skin. The principal hazard associated with crystalline silica relates to inhalation of respirable dust during manufacturing rather than to topical use of a finished product. It is not associated with comedogenicity.
Origin & sourcing
Natural mineral, mined and processed crystalline silica (silicon dioxide), then milled to cosmetic-grade powder.
Questions everyone asks
What does quartz do in a sunscreen?
It acts as a mineral powder that modifies texture and finish, such as adding a soft-focus or mattifying effect, and is not a UV filter.
Is quartz the same as silica?
Quartz is the crystalline form of silica (silicon dioxide); cosmetic listings may also use amorphous silica, which is a different physical form.