Pollux is a giant star, and like most stars, it's primarily composed of hydrogen and helium.

However, Pollux also contains a significant amount of heavier elements like carbon, oxygen, nitrogen, and iron. These heavier elements are formed through nuclear fusion in the star's core over its lifetime.

While the exact composition can vary slightly depending on the star's age and evolutionary stage, the basic composition of hydrogen and helium with a mix of heavier elements is typical for giant stars.