We have studied pressure distributions and area of contact as a function of load in a diamond indentor cell consisting of a flat diamond plate and diamond indentors of two different radii of curvature. The measurements were conducted with type Ia, IIa, and uncharacterized diamonds. Samples investigated were either ruby or ruby on a tantalum foil. In both cases, the ruby fluorescence was used to determine the pressure distributions. Previous suggestions that the elastic Hertzian solutions are applicable for plastic samples are not supported by these data. We conclude with comments on the prospects of the system for experimental high‐pressure research.