Ingredient dictionary

Calcium Aluminum Borosilicate

A fine, glass-like mineral powder made from calcium, aluminum, and borosilicate. It is mainly used to add light-reflecting sparkle and a smooth feel. It is on the label of 20 products in our library. Checked against our library November 6, 2026.

The catch: none for most people; check the full product list if your skin reacts easily.

What Calcium Aluminum Borosilicate does

Adds soft, light-reflecting shine
Smooths the texture of the formula
Helps pigments spread evenly

It is made by melting calcium, aluminum, boron, and silica into a glass, then grinding that glass into a very fine powder. Because it is a solid, inert material, it does not dissolve in water or oil. It stays in the formula as tiny particles.

Formulators use it because it reflects and scatters light. That gives lip gloss, eyeshadow, and mascara a soft shine or gentle sparkle. It also adds a smooth, slightly silky feel that helps products glide and spread. It is not usually linked with skin irritation, though how a product feels always depends on the full formula.

Good for

Good for people who like a glossy, sparkly, or soft-focus finish in lip, eye, and lash makeup.

Be careful if

Nothing in particular for most skin types.

Frequently asked questions

Is Calcium Aluminum Borosilicate safe for skin?

It is generally considered well tolerated in makeup and is not one of the ingredients usually linked with irritation. As with any cosmetic, people with very sensitive skin should patch test new products first and check the full ingredient list.

Why is it in my eyeshadow and lip gloss?

It adds light-reflecting shine and a smooth texture, which helps colors look brighter and feel comfortable to wear. It is most often found in lip gloss, eyeshadow, and mascara.