They exactly reflect the molecular, crystal-like structure of water in the solid state. In this state, each molecule is surrounded by four others, at which point the hydrogen is fixed, and the oxygen atoms arrange themselves in layers, forming a hexagon. After the first crystal is constituted, other water molecules aggregate in the corners of the initial molecule, forming the ramifications of the flake. “Even though they are always six-sided, crystals appear in various forms. The most familiar is in branches, but there are others such as plates, needles and prisms, depending on the temperature at which the crystal formed in the cloud”, says glaciologist Jefferson C. Simões, from the Federal University of Rio Grande do Sul (UFRGS).
