appear to have much higher ratios of \[Rb/Zr\]. Note that the \[Rb/Zr\] ratios in NGC 3201 appear similar to the highest values seen in the @tomkin99 sample. Unfortunately, the only star in the @abia01 sample with \[Fe/H\] $< -1.0$ does not have a Zr measurement. However, it does have \[Rb/Sr\] = $-$0.5 and \[Rb/Y\] = $-$0.6. If we assume for this star \[Rb/Zr\] = $<$\[Rb/Sr\],\[Rb/Y\]$>$ = $-$0.55, then the abundance is much lower than NGC 6752.

For elements heavier than Si, globular clusters and field stars tend to have very similar abundance ratios \[X/Fe\] at a given \[Fe/H\] [@gratton04; @sneden04]. Although the scatter is large and the sample sizes are limited, it would appear that cluster stars probably have similar, or perhaps slightly lower abundance ratios of \[Rb/Fe\] and \[Rb/Zr\] compared to field stars at a given \[Fe/H\].

Recall that we made substantial adjustments to the Zr abundance. While consideration of the Arcturus Zr abundances would appear to validate this adjustment, we briefly consider how the comparison of \[Rb/Zr\] would have fared if these corrections were not applied. In this case, the ratio \[Rb/Zr\] would decrease by roughly 0.3 dex for NGC 6752 as well as for the @gratton94 and 