Definition of Crystal
A Crystal is a solid body, which owns faces flat and well formed, with straight edges and a few sharp corners. In everyday life we are surrounded by crystals (common salt that we use in the kitchen, sugar, found in coins, the bones of the body or in the materials used in the construction).
Crystallography is the scientific discipline that studies the characteristics and properties of the crystals.
Most importantly a Crystal is to know its structure, which determines what are its physical or chemical properties. In this sense, should bear in mind that a Crystal has a geometric form regular.
Crystals and minerals
Interest in crystals originated through the study of minerals. The alchemists of the middle ages were wondering why each mineral had a certain geometric structure. Medieval scientists failed to respond to this type of questions. It was in the later centuries when he started to understand the configuration of matter. In this way, it noted that there was crystalline matter with a regular order. Crystallography replied to this comment and this discipline describes how the crystalline material is formed, what is its structure and is organised. In this way, a crystal as a homogenous solid which possesses a domestic in its polyhedral morphology can be understood.
Differentiating the Crystal ore, and the role of Mineralogy
To define what is a glass it is possible to understand what is a mineral, which is a naturally occurring crystalline solid. You could say that the mineralogy would be the knowledge that studies the chemical composition, structure, the origin and properties of the minerals from their crystalline composition.
Crystallography, one step further in the analysis
Crystallography goes beyond the mineralogy. In fact, nowadays it is science materials, whose objective is the creation of new materials applicable to new technologies and the industry. Some examples of this science are put in nanotechnology or the semi-conductivity.
The case of the carbon
A concrete example would be the case of the carbon. When the carbon crystallises forming a fixed structure it forms a mineral, Diamond (the hardest mineral known). If the carbon crystallises in another different structure can form graphite (one of the known less hard minerals). Thus, both minerals are identical from a chemical point of view and its organizational form is which makes them unique and different.