What are egg shells made of?

	Vocabulary
	calcium magnesium phosphorus protein

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). The remaining 5% includes calcium phosphate and magnesium carbonate and soluble and insoluble proteins.

Author: Fred Senese senese@antoine.frostburg.edu

General Chemistry Online! What are egg shells made of?