Stars that are rich in metals tend to be younger stars, and they tend to be richer in all of the elements above Helium. Moreover, you should note that any star is still mostly Hydrogen and Helium. Any other elements are much much less abundant.
When looking at stars, we can see the elements that are in their atmosphere from the spectrum. The star Mu Leonis (it is the top star in the "head" of the lion) has a stellar classification "K2IIIb CN 1 Ca 1", K2 means that this is an orange star, IIIb means that it is a giant star. CN1 Ca1 means that cyanide and calcium are particularly prominent in its spectrum.
Also, there may be Calcium in the core of highly evolved stars, just not for very long. A star that is fusing Argon to Calcium doesn't have long to live — about a day. So if the stellar core of Antares is getting very rich in Calcium right now, by tomorrow there will be a supernova.