Citations D. Athanasiadou et al. Nanostructure, osteopontin, and mechanical properties of calcitic avian eggshell. Science Advances. Published online March 30, 2018. doi:1126/sciadv.aar3219.

McGill University. "Cracking eggshell nanostructure: Implications for food safety." ScienceDaily. ScienceDaily, 30 March 2018. <www.sciencedaily.com / releases / 2018 / 03 / 180330145328.htm>.

To create their ‘eggshell ACP,’ the researchers first heated eggshells at 1,652 °F (900 °C) for an hour to decompose the organic matter and transform calcium carbonate into calcium oxide.

Now, researchers investigating eggshell structure have zeroed in on the fine structure and mechanical properties of chicken eggshells, and shell changes associated with chick hatching.