Glass, from which glass windows are made, is called ordinary glass. The chemical composition is sodium-calcium hexasilicate Na2CaS6O14, or Na2O**6S2. Modern science, technology, and even everyday life can not be satisfied only with this, because it has many shortcomings. This glass is easy to beat, but from a slight temperature drop is cracking.

Glass, from which glass windows are made, is called ordinary glass

In order for the glass to be thermo- and chemically resistant, it was well processed, to it are added potassium, magnesium, barium, aluminum, boron and the like. Thanks to this, laboratory glass, electric lamp, yen, pyrex are produced. Quartz glass is almost an ordinary silica SO2. For this, quartz is melted (usually rock crystal). In comparison with the usual, quartz has a 15 times lower coefficient of thermal expansion. Due to this, quartz products suffer thermal shock: you can, for example, strongly heat a quartz tube, and then lower it into cold water. Even after such "execution" on the glass will not be a single crack. Quartz freely transmits ultraviolet rays, and therefore is suitable for their generation (mercury quartz lamps - "mountain sun"). If you stain quartz glass with nickel salts, it becomes black and completely detains visible rays, but misses ultraviolet.

Without high-quality optical glasses, it would be impossible to think of modern telescopes, microscopes, periscopes and even ordinary glasses. Optical glass should be extremely transparent and highly refractive light rays. Such a glass can be welded, replacing, for example, a part of SiO2 with germanium dioxide GeO2. Valuable optical properties give glass and lanthanum oxide La2O3. Without lanthanum optics, you can not do without color photos. Lanthanum glass helped to reduce the size of the lens at the same luminosity. This greatly improved the quality of color images.

Glass, which contains both praseodymium and neodymium ("didymium"), absorbs well the ultraviolet rays and in addition is almost colorless. Protective goggles are made of it.

In the nuclear power industry, cerium glass is widely used - it does not dim from radiation, but also cadmium, which absorbs thermal neutrons. Glass that contains up to 15% of dioxide plutonium PuO2, is a promising nuclear fuel for reactors.