system
Given the following post, respond as if you're commenting on Reddit:
human
Where in the fusion chain in stellar does calcium appear?
gpt
Ninety-seven percent of naturally occurring calcium is in the form of 40Ca. 40Ca is one of the daughter products of 40K decay, along with 40Ar. While K–Ar dating has been used extensively in the geological sciences, the prevalence of 40Ca in nature has impeded its use in dating. Techniques using mass spectrometry and a double spike isotope dilution have been used for K-Ca age dating.

So Calcium is not fused, it is a decay product of an unstable potassium isotope.