In our daily life, we often come into contact with various types of glass materials. Besides the traditional flat glass, there are also glass materials with special properties such as ultra-white glass and high borosilicate glass, as well as common materials such as insulating glass and laminated glass. In order to let you know more about the difference between crystal and glass and the production method of glass, we collected information and compiled this article, hoping to help you distinguish crystal and glass quickly.
First, how to distinguish between crystal and glass

Method for quickly identifying crystal and glass
Imitation of crystal with lead glass and amethyst with high refractive index rare earth glass are more common in the market, and their mutual distinction methods are as follows:

(1) Touching the gemstone with the palm of your hand or mouth, it is rock crystal who feels cold; The glassy imitation crystal has a sense of temperature.

(2) Examining with a polarizer: When rotating 360 degrees under the polarizer, rock crystal has four bright and four dark changes, while the glassy imitation crystal has not changed.

(3) Check with dichroism: natural amethyst has dichroism, while glassy imitation crystal has no dichroism.

(4) Using feldspar with hardness of 6 as the test stone, the gemstone is scratched on the feldspar, and the crystal can be scratched with the same notch, and the glassy imitation crystal can slip. If there is no feldspar, it can also be directly scratched on the glass, and the crystal can be scratched, and the glassy imitation crystal can not be scratched.

(5) Test with a thermal conductivity meter: adjust the thermal conductivity meter to 4 squares of green to test the gem, and the crystal can rise to 2 squares of color, while the glass imitation crystal product does not rise, but rises to 1 square of color when the area is large.

Second, how is the glass produced?

Glass is a glass cup made of glass. Usually, the raw material is high borosilicate glass, which is fired at a high temperature of more than 600 degrees. It has the characteristics of high transparency, strong crystal sense and wear resistance.
The powder and clinker mixed according to the glass composition are put into a crucible kiln or a tank kiln (see glass melting furnace) for melting, and after melting, they are clarified into uniform glass liquid without bubbles, stones and stripes, and then cooled to a viscosity range suitable for the requirements of corresponding molding methods, and various molding operations are carried out:
1) blow-forming
There are two ways of manual and mechanical blow molding:
1. During artificial molding, hand-held blowpipe is used to pick materials from the crucible or the material inlet of the tank kiln, and the materials are blown into the shape of a device in an iron mold or a wood mold. Smooth round products are blown by rotary blowing method; The products with convex and concave patterns or irregular shapes on the surface are blown by static blowing. First, the colorless materials are blown into small bubbles, and then the colored materials or turbid materials are blown into the shape of a device, which is called nesting blowing. The particles with easily-melted colors are stained on the turbid nesting, and all colors naturally melt, which can be blown into natural scenery vessels. Tape-like opacifying material can be dipped in color material, which can be blown into wire drawing utensils.
2. Mechanical molding is used to blow a large number of products. After receiving the material, the blowing machine automatically combines the iron mold to blow it into a container shape, and after demoulding, the cap is removed to form the container. Press-blowing molding can also be used to blow the material into small bubbles (rudiments) first, and then continue to blow it into a container shape. It is more efficient and better in quality than simply blowing with a blowing machine.

2) press forming
During manual molding, materials are manually picked and put into an iron mold, the punch is driven, pressed into a device shape, solidified and shaped, and then demoulded.
Mechanical molding is automatic production, with large batch and high efficiency. Press molding is suitable for products with big mouth and small bottom that can be withdrawn from the punch, such as glasses, glass candlesticks, glass jars and glass bottles.
3) free forming
Also known as dieless molding, the materials are repeatedly baked and decorated or thermally bonded in front of the kiln. Because they are not in contact with the mold, the glass surface is bright and the shape and lines of the products are smooth. The finished products are also called kiln glass products.
4) centrifugal forming
The receiving material is in a rotating mold, and the glass spreads out and clings to the mold due to the centrifugal force generated by the rotation, and is taken out after solidification and setting. It is suitable for the forming of large glassware with uniform wall. Related concepts
crystal
Quartz Crystal is a colorless and transparent large Shi Ying crystal mineral. Its main chemical composition is silicon dioxide, and its chemical formula is SiO2. Crystal is colorless, purple, colored, green and smoky, etc., glass luster, transparent to translucent. Hardness 7, brittle, no cleavage; The crystal density is 2.56-2.66g/cm3, and the crystal refractive index is 1.544-1.553, which hardly exceeds this range. The dispersion of crystal is 0.013, and the melting point of crystal is 1713℃. When it is pure, it forms colorless and transparent crystals, and when it contains trace elements such as Al and Fe, it appears purple, color and brown. After irradiation, trace elements form different types of color centers and produce different colors, such as purple, color, brown and pink. Those containing associated inclusion minerals are called inclusion crystals, such as hair crystals and green ghosts, and the inclusions are rutile, tourmaline, actinolite, mica and chlorite.
crystal glass
Crystal glass, called artificial crystal, was born because rock crystal is very rare and difficult to mine, which can’t meet people’s needs. Crystal glass is made of Silica and lead oxide (other materials, such as potassium oxide and barium oxide, are used for lead-free crystals). Each factory has its own secret recipe, which makes the crystal particularly shiny. The clarity depends on the polishing technology and quality. Because of its high permeability, it can be made into various handicrafts and is greatly favored.