So I'm in the middle of planting a succulent garden where I used to have grass in a small "hell strip" by the street. (I'm realizing now that I'm running low on actual succulents plants as the space is a lot larger then I had anticipated)

Anyways I realized that the soil deep down was heavy in CLAY. It's really hard and has taken a long time to dig up.

For an ammendment I was recommended Gypsum which is supposed to add calcium and break up the clay in the soil.

Are there other benefits for Gypsum? Could I use it in my potted succulents?
Any recommendations as to how to use gypsum, what amount etc? I bought a large 50 lb bag for like $5