The chemical substance mercury sulfide, otherwise called cinnabar, is a very toxic compound. It is the most common mercury mineral. It has been used since antiquity as a dye. But when processed, this mineral can release toxic compounds and cause 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's blood". This is how mercury sulfide was called in the countries of the Ancient East for its red color. On a chip, this stone is so bright that it resembles drops of blood. In air, it quickly oxidizes, acquiring a bluish-gray color. Very rarely, this mineral exists in the form of individual crystals. Usually it is a solid mass or plaque. Cinnabar is also found in the form of veins, crusts and inclusions in limestone and clay rocks.
Another modification of mercury sulfide is the mineral metacinnabarite. It is a black powder, very rare in nature. Even rarer mineralswith the content of mercury sulfide - these are actashite, guadalcarcite, opophrite, saukovite and others.
Spread in nature
Mercury sulfide is the most common mercury mineral on Earth. It forms in hydrothermal deposits close to the surface. This mineral is mined together with quartz, pyrite, calcite and other rocks. The largest deposit of mercury sulfide, which has been developed for two millennia, is located in Spain. It is called Almaden, about 80% of the world's mercury reserves are mined here. There are also large deposits in Slovenia, Yugoslavia, and the USA. Separate ancient mines, which are still being developed, are in Rome, in the Donbass, in Central Asia, in Primorye.
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, therefore, mercury sulfide is so often used. The formula of this substance is HgS, otherwise it is also called mercury sulfide. A feature of a mineral is its physical and chemical properties:
- bright red;
- on a chip - glitters;
- thin plates of the mineral are almost transparent, reminiscent of a diamond;
- very fragile;
- has a high density, so it is very heavy;
- melts easily;
- if heated to 200 degrees, evaporates with the release of mercury vapor;
- dissolves in a mixture of nitric and hydrochloric acids.
Usage history
It is believed that cinnabar was known to mankind 15 thousand years ago. It was discovered in rock art. Even in ancient Rome, in Egypt and Byzantium, mercury sulfide was mined to obtain this metal and natural red pigment. Pieces of cinnabar were even used to make souvenirs.
The oldest deposits that have survived to the present are in Rome, Gorlovka, in the Ferghana Valley on the territory of Uzbekistan, in Tajikistan. They were developed in inhuman conditions, workers often died from poisoning.
Cinnabar was highly valued in antiquity because of its bright scarlet color. And it was mined 500 years before our era. In addition, it was used to obtain mercury. This metal was highly valued and used as a medicine for immortality. Due to its special properties, mercury was called liquid silver and was often used in alchemy. This metal was assigned the dominant place in all experiments.
Receive
Even in ancient China, artificial cinnabar was first obtained. By fusing mercury with sulfur, alchemists produced red mercury sulfide as early as the 9th century. And the artists of the Middle Ages in their paintings already used artificial cinnabar. Two methods are now used to obtain mercury sulfide: dry and wet. In dry production, mercury is mixed with sulfur and heated. This results in a black substance. It is then sublimated and condensed. And the wet method was tested back in the 18th century. In this case, mercury and sulfur were ground with water and mixed with caustic soda. After complex manipulationsred mercury sulfide was obtained. But it is less stable and turns black in the light.
The process of obtaining artificial cinnabar is very dangerous for humans, as it is accompanied by the release of toxic mercury compounds. Therefore, it is possible only in laboratory conditions in compliance with safety rules. In addition, the disadvantage of artificial cinnabar is that it can become bluish or almost black over time. This happens already in the paint layer.
Danger of this substance
Mercury is a very toxic metal. And cinnabar can also cause severe poisoning, as it can release mercury vapor even under normal conditions. And this is the strongest neurotoxic drug. It affects the brain, nervous system, negatively affects the kidneys and liver. Mercury vapor is odorless and can damage the respiratory tract if inhaled. Therefore, in terms of danger, mercury belongs to the first class - to the most dangerous chemicals. If a person is poisoned, convulsions, loss of sensitivity, paralysis of vital centers, depression of cardiac activity, hallucinations and death occur.
Mercury sulfide application
Cinnabar is the best source of mercury. But besides this, since ancient times, this mineral has been 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 even now. But in secular painting since the 19th century, it was replaced by safer cadmium paints. In addition, up toinventions of antibiotics, mercury sulfide was used as an effective cure 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;
- when making mirrors;
- for soldering many metals and gold mining;
- in pharmaceutics, for example, to preserve vaccines;
- back in the middle of the 20th century, it was part of dental fillings;
- alloys of mercury with other metals are widely used in jewelry;
- as a fungicide in agriculture.
