The Croatian Association of Crystallographers (CAC) organized a crystal growth competition for elementary and secondary school students in 2014. The competition consisted of performing crystal growth (crystallization) of a given material provided to the competitors. The goal of the competition was to make the largest and most regular crystal possible within a defined time limit.
Competitors can choose one of three categories:
- Crystal in a crystal: The goal is to prepare a crystal consisting of two types of substances, one in the middle and the other on the surface
- To prepare the largest and most regular crystal of the selected salt
- To prepare the largest and most regular crystal of the selected organic substance
Why research crystals?
Throughout history, people have been fascinated by the beauty and mystery of crystals. Two thousand years ago, the Roman naturalist Pliny the Elder admired the regular six-sided prisms of quartz crystals. At that time, the crystallization of sugar and salt was known in ancient India and China; sugar crystals were obtained from sugarcane juice, and salt crystals were obtained by evaporating brine. In the early Middle Ages, Egypt and Spain mastered the technique of cutting mineral crystals to decorate various objects (see box image). The German mathematician and astronomer Johannes Kepler first observed the symmetrical shape of snowflakes in 1611 and based on their shape, proposed their structure. The French mineralogist René Just Haüy proposed a model in 1774 according to which a crystal is formed by the assembly of small crystal units.
Wilhelm Conrad Röntgen discovered X-rays in 1895 and, for this discovery, received the first Nobel Prize in Physics in 1901. However, there are credible sources that Nikola Tesla experimented with X-rays before Röntgen
In the first half of the twentieth century, the methods by which we today determine the structure of crystals were discovered, which allow the investigation of the properties of materials dependent on their structure.