  I discuss the possibility that the large-scale segregation of metals that
accompanied planet formation might have left an imprint on the composition of
the primordial Sun. Motivated in part by recent Borexino measurements of CN
solar neutrinos, I stress how the additional linear metallicity dependence of
this flux could be exploited to constrain the composition of the solar core.
The gas in the core is arguably the earliest preserved sample of the material
out of which our solar system formed.
