A substance is classified as a glass, or as a glassy material, when it is not crystalline in structure, is a solid that has a vitreous and disordered state. Glass is the product of fusion of inorganic material through heat, then cooling to the solid state without forming a crystalline structure, where molecules form in a particular array on a plane or in a three dimensional and distinct structure.
Glass can contain silica as the main component, but can be made of all amorphous solids, material that melts and easily forms into an amorphous solid. This includes plastics, resins and other amorphous solids that do not contain silica. Potash glass contains calcium. Two of the other methods of producing glass include ion implantation and the “sol gel” technique.
The sciences of glass include glass science and physics which consider inorganic amorphous solids. Plastics and other organics are the focus of polymer science, biology, and other scientific fields. There are also glasses that incorporate carbonates, nitrates, and a host of other substances to create special properties, levels of opacity, or color.
The features of glass is that it is brittle, most often translucent or transparent, depending on the materials that are contained in it, and has many industrial, scientific, and decorative uses. Glass can be flat, in plates which can be installed to allow light to pass through, or for visual observation. Glass can be formed into containers of a myriad of shapes and sizes.
Glass can be distorted in many ways to develop optical properties for cameras, eyeglasses, telescopes or microscopes, and for magnifying objects that are viewed through the transparent forms. Glass, mixed with plastic, glass fiber, or even solid matter can be a thermal insulator. Glass can be formed in ways to amplify, color, and to aid in directing light. The uses and forms of glass in decorative, architectural, and artistic endeavors are seemingly endless.
A crystal is a solid material that has an arrangement of atoms, molecules, or ions in a well ordered, repeating pattern that can extend in all three dimensions. Most of the common metals are some form of crystals or poly crystals. Crystal twins are symmetrically grown together into a form called “crystal twins”. Gold and quartz are crystals which take on many forms when allowed to grow and form groups of great size, or when they are grown in confined spaces to create a grain that is invisible to the naked eye, or veins which travel underground.
Volcanic glass is actually igneous extrusive rock, where the magma has escaped into the atmosphere and cooled so quickly that the crystals in the magma have not had time to grow to a size that is visible to the naked eye, giving the rock a glassy appearance, while it is technically crystalline in makeup.
Lead crystal is actually a form of glass that is made by replacing the calcium in potash glass with lead oxide. This form of glass gives the clarity and can give the impression of finely carved, or smooth and transparent quartz or diamond, and is highly in demand for glassware and other decorative items.
Crystals have a wide variety of industrial and scientific uses in both western and traditional medicinal compounds. Crystals are essential for lighting lenses which amplifying and direct laser and other light, and in decorative and artistic materials. Synthetic, or man made crystals are popular in jewelry and in lighting fixtures, with the crystals as the most popular standard for decorative chandelier and jewelry. crystals. Quartz and other crystals are believed to focus positive and other energies that affect the human body and spirit.
CITATIONS
http://en.wikipedia.org/wiki/Lead_crystal
http://en.wikipedia.org/wiki/Crystal
http://en.wikipedia.org/wiki/Glass
