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 biomineralizationof the mollusc. In liquid crystals, twist–bend nematics have been predicted and observed. We presentand analyse evidence that the helical biomineral microstructure of mollusc shells may be formed from such aliquid-crystal precursor