I have no background in chemistry whatsoever. However, I'm very interested in sidewalk chalk composition. I read that chalk can be both either made out of gypsum or chalk (calcium carbonate). However, I'm confused, since a person that it is connected to a chalk (final product) manufacturer told me that the main ingredient in their product (chalk for kids) is sulfuric acid carbon.
As I said, my knowledge in chemistry is very reduced. I was just hoping that someone that knows well the subject can say if there can be a connection between the sulfuric acid carbon and gypsum.