Glass is a material created by man from the combination and fusion of minerals at high temperatures, which results in a transparent, brittle, hard and moldable by-product.
The crystal is all solid present in nature formed from chemical processes that create a crystal lattice, which is an ordered and symmetric structure of atoms and molecules.
The difference between glass and crystal is that glass is created with human intervention, while glass is a way in which the atoms and molecules of solid bodies are grouped.
| Glass | Crystal | |
|---|---|---|
| Definition | Amorphous and moldable material created from the fusion of compounds at high temperatures. | Solid material formed from the crystallization process. |
| Origin |
| It is found in nature. |
| Types |
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| Examples |
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| How it is recycled |
Glass waste goes in the green bin. | If you mean lead glass, commonly called “crystal,” it cannot be recycled. The lead glass waste goes into the gray container. |
What is glass?
Glass is a solid and amorphous material, created from the fusion of compounds such as silicon oxide (SiO 2 ), sodium carbonate (Na 2 CO 3 ) and calcium carbonate (CaCO 3 ), among others.
In nature, glass can be found:
- Like obsidian , a bright, strong, and sharp rock obtained by the cooling of volcanic lava.
- As tectics , which are glasses from meteorites that hit the Earth and which are very rare due to their origin.
The use of glass in its natural form is not that common and has been reduced to the elaboration of ornamental objects, hence man-made glass is much more popular.
On the other hand, industrial glass is classified into several types, depending on its chemical composition.
Types of glass and their uses
There are 4 types of glass, according to the components that make it up.
Sodium-calcium glass
It is made up of calcium, sodium, and silica. It is very easy to melt and that is why it is the cheapest type of glass on the market.
For a long time, it was recommended to avoid sodium-calcium glass for the manufacture of refractory containers for gastronomic use, because it did not tolerate changes in temperature and it used to break. However, this characteristic has been modified with the incorporation of a greater quantity of silica, which gives it greater resistance.
An example of sodium-calcium glass can be found in automotive glass.
Lead glass
It is a glass that is manufactured by substituting lead for sodium and calcium. It is very easy to melt and expand, which means that it expands when melted. It also has a refractory and UV absorbing quality.
Lead glass is often called lead crystal, or simply crystal. However, this is only a commercial one, as glass is not a crystalline structure, therefore glass objects do not exist.
In everyday life, lead glass is present in glasses, glasses or dishes.
Borosilicate glass
It is made up of silica and boron oxide. It does not melt so easily, it has a great refractory capacity and its expansion capacity is limited, which is why it is used to manufacture laboratory and kitchen materials, since they can withstand high temperatures without expanding and without the risk of breaking due to thermal shock.
An example of the application of borosilicate glass is refractory trays and containers.
Silica glass
It is the most difficult glass to melt, since it requires very high temperatures (more than 1500 ° C), as well as very sophisticated and expensive techniques to transform it into a final product.
Examples of silica glass can be seen on objects that require prolonged exposure to high temperatures, such as liners for furnaces or laboratory tubes.
What is crystal?
The crystal is a solid, transparent structure, with an ordered, symmetrical molecular arrangement and regular geometry. It is abundant in nature, and is formed from crystallization, a process in which atoms or molecules form bonds to create an elemental unit called a unit cell , a cube-shaped or parallelepiped structure.
In everyday life, the term “crystal” is used to refer to lead glass, used in the manufacture of objects such as glasses and goblets. This name is incorrect, since glass is a material with an asymmetric and disordered molecular structure, therefore, they are two different materials.
Unit cells are classified into various groups based on their characteristics. These groups are known as crystal systems.
Crystalline systems
According to the length of the sides of the unit cell, the arrangement of its axes and angles, crystals are classified into seven large crystal systems.
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