Helical microstructures in molluscan biomineralization are a biological example of close packed helices that may form from a colloidal liquid crystal precursor in a twist-bend nematic phase

We demonstrate that nature has produced a close-packed helical twisted filamentous material in the biomineralization of the mollusk. In liquid crystals, twist-bend nematics have been predicted and observed. We present and analyze evidence that the helical biomineral microstructure of mollusk shells may be formed from such a liquid-crystal precursor.