Which substance is used in pearl and frosted enamels for their effect?

Bismuth oxychloride is used in pearl and frosted enamels primarily for its unique pigment and reflective properties. This substance has a pearlescent effect that gives the enamel a shimmering, lustrous appearance, which is particularly desirable in cosmetic formulations. The light-reflecting qualities of bismuth oxychloride enhance the aesthetic appeal of nail products by creating a multi-dimensional look that resembles the sheen of pearls. It is often chosen for its safety profile and effectiveness in achieving the desired color and finish, making it a preferred ingredient in the formulation of various nail products.

In contrast, the other substances listed do not contribute to the characteristic effects found in pearl and frosted enamels. Silicone is more commonly used for its smoothing properties in other cosmetic applications, glycerol serves as a humectant to retain moisture, and formaldehyde is primarily associated with preserving properties rather than providing a visual effect. Therefore, bismuth oxychloride stands out as the key ingredient for achieving the desired finish in these specific enamels.