In this work we determined the influence of potassium-to-sodium ion exchange in the nonlinear refractive value (n2) of Corning's Gorilla Glass (GG). Due to the production process, GG has a rich potassium surface in comparison to the original sodium matrix glass. In order to determine the nonlinear cross-section profile, we have used a highly sensitive nonlinear elliptical rotation spatial measurement. Using a simple model, where the nonlinearity varies exponentially with depth, we observed that the value of the nonlinear refraction at the surface is about 22% greater than that of the matrix interior with a penetration depth constant of ∼50 μm.