Light: Science & Applications (2026). DOI: 10.1038/s41377-026-02263-z"> Directional dark-field projection of the enamel of a human permanent MIH-tooth. Credit: Light: Science & Applications (2026). DOI: 10.1038/s41377-026-02263-z Whether in tooth enamel or in nanomaterials made of silicon, the orientation of tiny internal structures often determines the properties of a material. A new X-ray method can even make this nano-order visible when the structures are actually too small to be imaged directly. The method was developed by an international team led by the Helmholtz Center Hereon, and it opens up new possibilities to investigate materials and biological structures. The research is published in the journal Light: Science & Applications . In medical X-ray imaging, the picture is created by the varying attenuation of X-rays in the body. In order to examine materials or biological tissue in detail, experts use advanced techniques that provide additional information, such as dark-field imaging.…