  The individual characteristics of C, N, O, Na, Mg, Al, Si, and Fe on
isochrones have been investigated in this study. Stellar models have been
constructed for various mixtures in which the content of each element is
changed up to the extreme value reported in recent studies, and the changes in
isochrone shape have been analyzed for the various mixtures. To express the
abundance variation of different elements with a single parameter, we have
focused on the relative changes in the total number of metal ions. A review of
the shape changes revealed that Na, Mg, and Al work the same way in stellar
models, as the well-known fact that C, N, and O have the same reactions in the
stellar interior. In addition, it was found that in high-metallicity conditions
the influence of Si and Fe on the red giant branch becomes smaller than that of
Na, Mg, and Al closer to the tip. Furthermore, the influence of Fe on the main
sequence is larger than that of Na, Mg, Al, and even Si.
