Bismuth oxychloride is an inorganic compound of bismuth, which is an element naturally found in the rare mineral bismoclite. However, the bismuth oxychloride used in cosmetics is a synthetic white or nearly white amorphous or finely crystalline powder. In cosmetics and personal care products, bismuth oxychloride is used as a colorant. It imparts a white color, as well as provides an iridescent (shiny) effect. In fact, bismuth oxychloride has been used in cosmetics since the days of ancient Egypt.

Bismuth oxychloride is primarily used in the formulation of mineral makeup powder, but can also be found in nail products, eyeshadow, lipstick, and some skin care products.  In mineral makeup powder, bismuth oxychloride provides a white shimmer or pearlescent matte finish to the face. By reflecting light away from the skin, bismuth oxychloride helps to conceal blemishes, wrinkles, and other imperfections. It also provides a silky feel and has excellent dermal adhesion, which enables makeup to stay on the skin for long periods of time. Bismuth oxychloride may appear on an ingredient label under its INCI name, which is CI 77163.