The chemical substance mercury sulfide, also called cinnabar, is a very toxic compound. It is the most common mercury mineral. It has been used since ancient times as a dye. But when processed, this mineral can release toxic compounds and causes poisoning. Therefore, now cinnabar is used only for the extraction of mercury, which is used in industry and medicine.
Mineral mercury sulfide
It is called cinnabar. This word comes from the ancient Persian combination "dragon blood." That is how in the countries of the Ancient East, mercury sulfide was called for its red color. On a chip, this stone is so bright that it resembles a drop of blood. In air, it quickly oxidizes, acquiring a bluish-gray color. Very rarely, this mineral exists in the form of individual crystals. Usually this is a solid mass or plaque. Cinnabar is also found in the form of veins, crusts and intersperses in limestone and clay rocks.
Another modification of mercury sulfide is the metacinnabarite mineral. This is a black powder, very rare in nature. Even more rare minerals containing mercury sulfide are Aktashit, Guadalcarcite, Opofrit, Saukovit and others.
Spread in nature
Mercury sulfide is the most abundant mercury mineral on Earth. It is formed in hydrothermal deposits close to the surface. This mineral is mined together with quartz, pyrite, calcite and other rocks. The largest mercury sulfide deposit, developed for two millennia, is located in Spain. It is called Almaden, it produces about 80% of all global mercury reserves. There are also large deposits in Slovenia, Yugoslavia, and the USA. Separate ancient mines, which are still being developed, are in Rome, the Donbass, Central Asia, and Primorye.
The properties
This mineral contains over 80% mercury. It is he who is the main source of this metal. Since mercury has long been known and used in industry, mercury sulfide is so often used. The formula of this substance is HgS, otherwise it is also called mercury sulphide. A feature of the mineral is its physical and chemical properties:
- bright red color;
- glitters on the cleavage;
- thin mineral plates are almost transparent, resembling a diamond;
- very fragile;
- has a high density, therefore very heavy;
- easy to melt;
- if heated to 200 degrees, evaporates with the release of mercury vapor;
- soluble in a mixture of nitric and hydrochloric acids.
Usage history
It is believed that cinnabar was known to mankind as early as 15 thousand years ago. She was discovered in cave painting. Even in ancient Rome, in Egypt and Byzantium, mercury sulfide was mined to produce this metal and natural red pigment. Pieces of cinnabar were used even for making souvenirs.
The oldest deposits, preserved to the present, are in Rome, Gorlovka, in the Ferghana Valley on the territory of Uzbekistan, in Tajikistan. They were developed under inhuman conditions, workers often died from poisoning.
Cinnabar was very much appreciated in antiquity because of its bright scarlet color. And they mined it for another 500 years BC. In addition, it was used to produce mercury. This metal was very much appreciated and used as a medicine of immortality. Because of its special properties, mercury was called liquid silver and was often used in alchemy. This metal was given the dominant place in all experiments.
Getting
Even in ancient China, artificial cinnabar was first obtained. By fusing mercury with sulfur, alchemists obtained red mercury sulfide back in the 9th century. And the artists of the Middle Ages used artificial cinnabar in their paintings. Two methods for producing mercury sulfide are currently used: dry and wet. In dry production, mercury is mixed with sulfur and heated. This produces a black substance. It is then sublimated and condensed. A wet method was tested in the 18th century. In this case, mercury and sulfur were ground with water and mixed with caustic soda. After complex manipulations, red mercury sulfide was obtained. But it is less stable and blackens in the light.
The process of producing artificial cinnabar is very dangerous for humans, as it is accompanied by the release of toxic mercury compounds. Therefore, it is possible only in a laboratory environment in compliance with safety rules. In addition, the disadvantage of artificial cinnabar is that over time it can acquire a bluish or almost black shade. This happens already in the paint layer.
Hazard of this substance
Mercury is a very toxic metal. And cinnabar can also cause severe poisoning, as it is capable of releasing mercury vapor even under normal conditions. And this is a powerful neurotoxic drug. It affects the brain, nervous system, negatively affects the kidneys and liver. Mercury vapor is odorless and, when inhaled, affects the respiratory tract. Therefore, in terms of danger, mercury belongs to the first class - to the most dangerous chemicals. When a person is poisoned, convulsions, loss of sensitivity, paralysis of vital centers, inhibition of cardiac activity, hallucinations and death occur.
Mercury Sulfide: Application
Cinnabar is the best source of mercury. But besides this, from ancient times this mineral was used as a bright natural dye. Cinnabar was used as a paint for painting icons, drawing capital letters in the Bible, and making souvenirs. In icon painting, it is often used as a paint now. But in secular painting from the 19th century, it was replaced by safer cadmium paints. In addition, before the invention of antibiotics, mercury sulfide was used as an effective medicine for syphilis, antiseptic and laxative.
Now mercury extracted from cinnabar is widely used in industry:
- in the manufacture of thermometers;
- in electrical engineering;
- for filling fluorescent lamps;
- for the production of barometers;
- in the manufacture of mirrors;
- for soldering many metals and in gold mining;
- in pharmaceuticals, for example, for preserving vaccines;
- back in the mid-20th century, it was part of dental fillings;
- alloys of mercury with other metals are widely used in jewelry;
- as a fungicide in agriculture.