What is the compound present in egg shell which makes it a good alternative for making face powder?

I need it to be specific...What is the compound present in egg shell which makes it a good alternative for making face powder?
The main ingredient in eggshells is calcium carbonate (the same brittle white stuff that chalk, limestone, cave stalactites, sea shells, coral, and pearls are made of). The shell itself is about 95% CaCO3 (which is also the main ingredient in sea shells).





My guess is most people are not allergic to it than other chemical compound, so it is a good alternative.What is the compound present in egg shell which makes it a good alternative for making face powder?
I believe it is calcium carbonate
According to Wikipedia: ';The eggshell is approximately 95% calcium carbonate crystals, which are stabilized by a protein matrix. Without the protein, the crystal structure would be too brittle to keep its form. ';





So it is probably calcium carbonate, the chemical name for chalk.





Lots of face powders are made of talc, which is a white powder that is different from chalk.