The main differences between the two pigments are in their composition, the pigment ‘s shape, and the way how these two properties determine their interaction with light.
Xirallic pigments are a flat sheet of aluminum oxide. They are characterized by a high gloss under intense light that sparkles as light falls upon directly on its surface. These pigments are often very chromatic.
The origin of pearl pigments can be organic, and they are a silicon oxide sheet. The gloss is less pronounced, but they have more color variety and available sizes than the xirallic pigments. In addition, they can present color interferences that, depending on the angle of observation, can create totally different colors.
In both cases, the color is determined by the coverage of the sheets, which can be, for example, iron oxide or titanium oxide.
Usually they act in combination with solid and/or metallic pigments since they would be too transparent on their own. They frequently compose the most sophisticated colors on the market and they are also the most expensive paints in a car dealership.
Interesting fact: Out of the 5 angles of our XCrom spectrophotometer, the ones that collect most of their effects are angles 15 and 25.