Eggshells of chickens are formed from amorphous calcium carbonate nanoparticles which are transformed into ordered crystals by protein mediation.

Eggshell this a thin yet relatively strong material due to its composite makeup of ordered calcium carbonate crystals and . A layer of crystalline calcite clusters overlays partially aligned calcite columns. The mineral begins as amorphous calcium carbonate nanoparticles, then is transformed to ordered crystals by the presence of C-type lectin-type proteins. The proteins attach themselves to the nanoparticles, initiating crystal transformation, and then detach while crystal growth continues.

Growing a good egg: Metadynamics simulations show that the eggshell protein ovocleidin-17 induces the formation of calcite crystals from amorphous calcium carbonate nanoparticles. Multiple spontaneous crystallization and amorphization events were simulated; these simulations suggest a catalytic cycle that explains the role of ovocleidin-17 in the first stages of eggshell formation (the picture shows one intermediate of this cycle).

Image: Sun Ladder /
Last Updated August 23, 2016