Homogeneity studies on the geochemical exploration reference samples GXR‐1 through GXR‐6 were initially based on analyses by methods of 10–30 percent relative standard deviations (rsds). Use of the materials for high‐precision method validation requires that homogeneity be established using methods having rsds less than 1.0 percent, if possible. The current homogeneity study shows distinct in homogeneities in all GXR materials for some major, minor, and trace const