Blucher Proceedings 23 rd ABCr , Vitória, Setembro 2017 Uruguay´s National Crystal Growing Competition N. Alvarez, I. Aguiar, M. Barros, I. Galain, R. Keuchkerian, M. Mombrú, I. Núñez, G. Peinado, M. Rodríguez, L. Suescun. Facultad de Química, Universidad de la República, Uruguay. During the International Year of Crystallography, in 2014, Uruguay held the first National Crystal Growing Competition (CNCC, for Concurso Nacional de Crecimiento de Cristales, in Spanish). It was organized by an interdisciplinary group of scientists from different areas such as physics, organic, inorganic, bio- and radio- chemistry, among others. The main goal, aligned with the ones set by the IUCr, was to reach the community introducing them to the exciting world of crystallography by involving young people in growing a single crystal. Throughout the first three editions more than 800 people, ages 7 to 30, participated on the CNCC. The competition involved tutor´s workshops, provided by the organizers, to gain specific knowledge in growing crystals, growing the actual single crystal, keeping detailed records of the experiment and presenting the work as a video at the end to be judged. Participants were judged by the weight and quality of the crystal grown as well as their records of the experiment in terms of creativity and scientific rigor. Introduction Crystallography is an interdisciplinary science that helps shape modern science through structural determination of numerous substances, from simple salts to complex macromolecules. The importance of this discipline can be seen by the 29 Nobel prizes awarded for various contributions in physics, chemistry and biology. Due to its influence in modern science the United Nations´ General Assembly declared 2014 as the International Year of Crystallography (IYCr) celebrating 100 years since the Nobel Prize was awarded to Max von Laue for the discovery of the diffraction of X-rays by crystals. The International Union of Crystallography launched a worldwide initiative aiming mostly to increase public awareness of the science of crystallography and how it underpins most technological development in our modern society. To this end an International Crystal Growing Competition was held, among a series of activities that included specialized workshops, exhibitions, films, and other forms of outreach. In Uruguay, various activities took place to commemorate IYCr including an Openlab, theme talks, mineral exhibition, crystals´ treasure hunt, and the first CNCC. Aims of the CNCC  bring participants closer to the world of crystallography and its importance by developing an experimental task: growing a large single crystal.  encourage interest in science and research through a physicochemical experiment that does not require specific materials or laboratory conditions  train participants in the application of the scientific method by carrying out a rigorous task that requires commitment  emphasize the importance of process recording, as well as the communication of results  stimulate team work, knowledge and experience exchange in a non-structured environment  encourage participation in the International Crystal Growing Competition Participants and categories All kids, teenagers and young adults motivated by scientific knowledge and participating on a planned physicochemical experiment were encouraged to participate with the help of a tutor who would have previously undertaken a crystal growth workshop. The first edition, aimed at growing a large single crystal, had three categories as follows: 1) elementary school children, 2) highschool students and 3) general public. As of the second edition