The crystallization Is the process through which formed solids are formed into complex structures traditionally called crystals.
The solids or crystals produced during crystallization can be of four types: ionic, molecular, covalent network and metallic.
- Ionic, like salt, are soluble in water and conduct electricity.
- Molecules, like ice, do not conduct electricity. Some are dissolvable while others are not.
- Covalent networks, such as diamond, are not dissolvable and do not conduct electricity either.
- Finally, metallic, such as mercury, are malleable, conductive electricity and are lustrous.
Crystallization consists of two phases: nucleation (in which the crystalline phase initiates) and crystal growth (in which there is an increase in the size of the particles that make up the crystal).
The process of crystal formation can occur naturally (as with the formation of gemstones, stalagmites, stalactites or even snowflakes) or artificially (such as chocolate, ice made by our refrigerators or Molasses made in the candy factories).
In this article, we will present examples of crystallization, both natural and artificial.
1- Snowflakes
Snowflakes are formed through a natural crystallization process.
It is known that each snow crystal is unique. This is due to the conditions that arise during the second phase of crystallization (growth).
The different geometric forms that the snow crystals present are due to the conditions that they must face during the growth of the crystal.
2- Stalagmites
Stalagmites are structures that can be found in caves, specifically in soils (growing upwards). These are formed from calcium compounds.
These are formed from the crystallization of the calcium salts found in the water falling from the roofs of the caves.
3- Stalactites
The stalactites, like the stalagmites, are of calcium and are found in the caves. They differ from the latter because they hang from the ceilings. They are formed by the crystallization of the salts of calcium present in the water that infiltrates the caves.
4- Diamond
The diamond is a precious stone that is formed from the crystallization of pure carbon. This is the hardest material known on the planet.
Their formation can be natural, as it happens with the diamonds that are in mining, or synthetic deposits.
5- Ruby
Ruby is a reddish colored crystal that forms from the crystallization of aluminum oxide (coridon).
6- Quartz
Quartz is a gem that is formed from the crystallization of silicic anhydride. It is one of the minerals that more abound in the rocks and its color is variable.
7- Peridot
Also called olivine, this precious stone is formed thanks to the crystallization of iron and magnesium. It is greenish in color and usually has the shape of a rhombus.
8- Silicates
Silicates are materials created by the crystallization of silica and other elements (iron, aluminum, calcium, magnesium). These are present in all rocks.
9- Salt
Salt is the most common example of crystallization. This can form both natural (like sea salt) and artificially (as in the case of table salt).
10- Sugar
After salt, sugar is one of the most common crystals. This crystal is formed through a series of complex industrial processes in which sugarcane juice is taken and subjected to an artificial crystallization process.
11- Ice
Ice is a crystalline molecular solid that is formed through processes of crystallization, similar to those involved during the formation of snowflakes.
The process of ice formation can be natural (in areas where the temperature is below 0 ° C) or artificial (such as that in freezers).
12- Creamy ice cream
The creamy ice cream contains a number of crystals that give it the ultimate soft texture. Among the crystals that contain the creamy ice cream, are the lipid crystals (formed from fats) and ice crystals. It should be noted that some ice cream also contain lactose crystals.
In this sense, ice cream is obtained through various processes of artificial crystallization (one for lipids, one for ice and another for lactose).
13- Chocolate
Like creamy ice cream, bar chocolate contains lipid crystals that melt in our mouth when we eat a piece of this sweet.
When the chocolate is made, it must be seasoned and it is during this process that the lipid crystals are formed. These crystals come from cocoa butter, which is responsible for the structure, texture and appearance of chocolate. This is an example of artificial crystallization.
14- Candies
The candies are made with crystals of sugar, so it can be said that two processes of crystallization intervene: the first for the formation of sugar and the second for the formation of molasses.
Other examples of crystallization are:
15- Jasper, precious stone.
Photo retrieved from pixabay.com
16- The sapphire, precious stone.
17- The amethyst, precious stone.
18- The emerald, precious stone.
19- The lapis lazuli.
20- Graphite.
21- Copper.
22- The mercury.
23- Lithium.
24- Calcium.
25- Sodium.
26- Magnesium.
27- Beryllium.
28- Benzoic acid.
29- The aluminum oxide.
30- Barium chloride.
References
- Crystallization. Retrieved on July 17, 2017, from cheresources.com
- Crystallization in foods. Retrieved on July 17, 2017, from storify.com
- Handbook of Indestructial Crystallization. Retrieved on July 17, 2017 from books.google.com
- Crystallization of Organic Compounds. Retrieved on July 17, 2017 from books.google.com
- Examples of Crystallization in Daily Life. Retrieved on July 17, 2017, from chegg.com
- Crystallization: Basic Concepts and Industrial Applications. Retrieved on July 17, 2017 from books.google.com
- Mesocrystals. Retrieved on July 17, 2017, from books.google.com.