This special issue comprises 24 selected articles from those presented in the International conference “Crystallization 2017” organized by the Spanish Society of Ceramics and Glass (SECV) under the auspices of the International Commission on Glass (ICG) and celebrated in Segovia from the 10th to 12th September 2017.

The issue includes a very special contribution entitled “Updated definition of glass-ceramics”, the authors of which are very well-known scientists and technologists in the field of glass. The work was coordinated by the TC07 chair of the ICG on Crystallization and Glass-ceramics, Prof. Joachim Deubener. The two conference chairs, María Jesús Pascual and Alicia Durán, served as guess editors of the special issue.