Mayonnaise is a heteregoneous mixture. It is an emulsion which consists of fine particles of water and oil. Heterogeneous mixtures are mixtures that do not have a uniform composition though out the whole mixture resulting to non-uniform properties. In this mixture, when you get sample at different points, you would would have different compositions of the components and they will have different properties. Other examples are orange juice with pulp, salad dressing, concrete, chocolate chip cookies. The opposite of this mixture is called the homogeneous mixture where it exhibits uniform composition throughout the mixture.