Without this stone, the most sought-after metal of our time would not exist. The demand for this rare mineral is growing every day, and its deposits in the nature are few.
Cryolite, which looks like a block of ice, was first discovered in the permafrost and snow of Greenland at the end of the 18th century, during the Danish colonization. Because of its resemblance to frozen water, it was called "cryoslitos," which means ice stone in Greek. The natives, long familiar with the mineral, ascribed magical powers to it. The population has noticed that when a piece of the stone dipped into a glass of water, it vanished. It was believed that problems and illnesses would dissolve with it. Scientists were later able to explain this peculiarity: it turned out that the mineral has the same angle of light refraction as water, so if you drop it in the liquid it will become invisible.
For almost ninety years since its discovery, cryolite had no worthwhile use until it was used to extract aluminum from rocks. The familiar metal, considered one of the most sought after in the twenty-first century, is almost never found in its pure form on Earth, but only as part of ore.
Aluminum cannot be smelted in a furnace like iron, for example. A new technology that made it possible to produce aluminum on a large scale and at low cost was invented in 1886 independently of each other by the Frenchman Heroux and the American Hall.
At first, aluminum-rich ores such as bauxite, nepheline, alunite, and kaolin were treated with alkali to produce aluminum oxide, or alumina, free of impurities. This mixture was then electrolyzed. For this purpose, the tank capacity was filled with molten cryolite, which created a conductive environment at a temperature of 950 degrees Celsius. The role of cathode was played by the bottom of the bath, and the role of anode was played by carbon blocks immersed in cryolite. Then the alumina was fed into the bath and an electric current was passed through all of its contents. Under its influence the bond between aluminum and oxygen was broken - the metal was deposited at the bottom of the bath, and the oxygen combined with carbon to form carbon dioxide. Next, alumina was added to the tank again, and the process was repeated, with the pure metal being extracted as it accumulated.
In addition to efficiency, the use of cryolite chips was a profitable solution: as little as 32 kilograms of crushed rock was enough to produce one ton of aluminum. Half of this amount could be reused.
After that, aluminum production began to develop rapidly. The metal began to be actively used in shipbuilding and automobile construction, but the real revolution was made in the aviation industry. For this it forever earned its second name - "the winged metal".
On the seventeenth of December 1903, the American aviators brothers Wilbur and Orville Wright flew the first controlled aircraft in the history of mankind. In order to make it fly, they developed a new lightweight engine, most parts of which were made of aluminum and, of course, the airframe was also made of aluminum.
From that moment on, one of the single deposits of the mineral, located in Greenland, did not stop mining the rare stone for almost a century. The shortage of cryolite for industrial needs became so obvious that it led to the idea of creating an artificial analog of the mineral. Soviet scientists worked on this task for almost ten years, and in 1933, the first integrated factory was opened near Sverdlovsk, which specialized in the production of synthetic cryolite. Interestingly enough, the mineral is no less in demand after all this time, and is still used in industry for the same purposes as it was more than a hundred years ago.
However, besides its obvious benefits, cryolite can be harmful: the presence of fluoride ions makes it poisonous. Any interaction with it in large quantities is dangerous to health. This is especially true for a laboratory-grown mineral in the form of a white powder. Cryolite is flammable and can easily ignite, and it releases toxins when exposed to high temperatures. Partly for this reason, but also because of its brittleness, rarity, and difficulty of extraction, the mineral has not found its way into the jewelry business. However, and thought not very common, jewelry pieces containing this stone can still be found in the collections of international brands.
Today, there are only a few large deposits of cryolite in the United States, Greenland, Russia, and New Zealand, and new deposits are extremely rare. It is believed to be much cheaper to synthesize the mineral in a laboratory than to find it and extract it from the entrails of the earth.
Translated by Diego Monterrey, for Northwest Forpost.
