Ordinary glass is a mixture of silicates, while glass is silica. Glass is amorphous, but it is crystalline. Amorphous crystals are isotropic, and the optical properties of crystals are directional-some have large refractive index and some have small refractive index-which determines that crystal materials cannot be used as optical materials.

Glass is more expensive because it requires higher purity silica and higher process quality.

Extended data:

1, which is one of the main rock-forming minerals, is generally called low-temperature chronotropic (α-chronotropic) and is the most widely distributed mineral among chronotropic minerals. The generalized response time also includes high temperature response time (β-response time) and coesite. [ 1]? The main component is silicon dioxide, which is colorless and transparent, often containing a small amount of impurities, and becomes translucent or opaque crystals with a hard texture.

Yingshi is a kind of mineral resource with very stable physical and chemical properties, and its crystal belongs to the three-crystal oxide mineral. Timely block, also known as silica, is mainly the raw material for producing quartz sand, as well as the raw material for timely refractory and ferrosilicon firing.

It is a mineral composed of silicon dioxide, and its chemical formula is SiO2. Pure time is colorless and transparent, because it contains trace pigment ions or finely dispersed inclusions, or colored centers, which reduces transparency, so it has various colors. It has glass luster, and the fracture surface is oily luster. Hardness 7, no cleavage, conchoidal fracture. The specific gravity is 2.65. Piezoelectric.

Colorless and transparent seasonality is called "Krystallos" by the Greeks, which means "Bai Bing". They are sure that it is solid and durable ice in time. Ancient people in China believed that cold crystals in their mouths could quench their thirst.

2065438+07171The list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization on October 27th was preliminarily sorted out for reference. Crystalline silica dust exists in the list of carcinogens in the form of or square.

2. Glass is an amorphous inorganic nonmetallic material, which is generally made of various inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc.). ) is the main raw material and a small amount of auxiliary raw materials. Its main components are silicon dioxide and other oxides.

The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O CaO 6SiO2, etc. The main component is silicate double salt, which is an amorphous solid with irregular structure. Widely used in buildings, used for wind and shading, belonging to a mixture. In addition, colored glass doped with oxides or salts of certain metals shows color, and tempered glass made by physical or chemical methods. Some transparent plastics (such as polymethyl methacrylate) are sometimes called plexiglass.