Cinnabar - A Beautiful But Toxic Mineral, Ore and Pigment

Cinnabar is a beautiful bright red, orange red or brick red mineral that is sometimes known as vermilion. In ancient times cinnabar was ground into a powder and used as a pigment for art and decoration and in cosmetics. Cinnabar is still used in artists’ paints today. It’s a mercury ore and is made of a compound called mercury (ll) sulfide (also known as mercuric sulfide), which has the chemical formula HgS. Most of the world’s mercury supply is obtained from cinnabar. Mercury and mercury compounds are toxic to humans, although cinnabar is not as poisonous as some other forms of mercury.

Cinnabar is usually found in rocks that form near volcanic activity or in hot springs. It’s produced near the Earth’s surface from hot liquids that bubble up from deeper in the Earth. Major cinnabar producers today include Spain, China, Italy, Serbia, Slovenia and parts of the United States.

Like several other red materials in nature, cinnabar was often known as “dragon’s blood” in earlier times. Its vibrant red color was a great attraction for people.

The Mayan people used cinnabar to decorate burial chambers, the sarcophagi and the dead bodies of important members of their society. Ancient Romans created paintings and decorated statues and their faces with ground cinnabar mixed with a medium such as egg yolk or plant gums. Ancient Chinese people used cinnabar in their famous red lacquers and in special inks. The technique for making artificial vermilion from mercury and sulfur was apparently first devised in China, in the eighth century. Vermilion from China is sometimes known as China Red. Earlier women in India wore vermilion along the parting of their hair and in a dot on their foreheads to indicate that they were married, and some modern Indian women still follow this custom, but today the pigment, known as sindoor, is made of turmeric, lime juice and other substances instead of cinnabar.

In more recent times, powdered cinnabar, or vermillion, was added to candies as a food coloring, although it's no longer used for this purpose. However, cinnabar is still part of many traditional Chinese medicines. Cinnabar, as natural or artificially made vermillion, is sold today as an artist’s paint, with a warning to avoid ingestion and skin contact. Some artists use cadmium red as a replacement for vermillion.

The word "cinnabar" is sometimes used to name items unrelated to the cinnabar mineral in order to convey an exotic impression. For example, Cinnabar perfume contains no mercury. Cinnabar jewelry and jewelry boxes are usually made of wood that is covered by a red lacquer or a red resin polymer and then imprinted with a design. The jewelry doesn't contain the cinnabar mineral, since mercury compounds shouldn't stay in contact with the skin.

To extract mercury from cinnabar the cinnabar is heated. The mercury escapes from the cinnabar as a gas, which is then cooled and condensed to make liquid mercury. Mercury is the only metal that is liquid at room temperature. The early alchemists called it “quicksilver” due to its silver color and the fact that when it’s placed on a surface it forms beads which roll around as though they are alive.

Mercury exists in three forms – elemental mercury (pure metallic mercury), organic mercury (mainly methylmercury, the form found in some fish) and inorganic mercury, such as the mercury (ll) sulfide that makes up cinnabar.

The severity of mercury poisoning in humans depends on many factors, including the form of the mercury, the way in which the mercury is absorbed into the body (through ingestion, inhalation or skin absorption) the dose of mercury absorbed, the duration of the exposure, the frequency of the exposure and the age and health of the affected person. Mercury poisoning can result in damage to the nervous and muscular systems, as well as damage to the gastrointestinal tract, kidneys and respiratory system.

Inorganic mercury such as the mercury found in cinnabar is the least toxic form of mercury, but it's still poisonous. Inorganic mercury is absorbed through the lining of the digestive tract, but in lower quantities than organic mercury. Since it doesn’t vaporize much at room temperature not much inorganic mercury is inhaled – unless it’s in the form of dust, which is dangerous for the lungs. Small amounts of inorganic mercury compounds can be absorbed through the skin, and contact with high levels of inorganic mercury can cause skin rashes. Although it’s less likely to cause nervous system damage than other forms of mercury, chronic exposure to inorganic mercury can damage the kidneys and the nervous system too.

Although there is some uncertainty about exactly how poisonous cinnabar is inside the human body, and about how much cinnabar we need to be exposed to in order to experience harmful effects, scientists generally recommend that we limit our exposure to all mercury compounds, including inorganic mercury, as much as possible.

People using cinnabar are warned not to inhale cinnabar dust and to be very careful when breaking the mineral. The mineral mustn’t be ingested or licked, and mustn’t be heated, which might trigger mercury vapor release. Hands should always be washed if cinnabar is touched, and powdered cinnabar or artificial vermilion being used in a paint shouldn't come in contact with the skin. One potentially serious problem is that sometimes drops of liquid mercury can be found in a piece of cinnabar mineral, which are more dangerous than the cinnabar itself. Liquid mercury releases a poisonous vapor.

Cinnabar is a beautiful but potentially dangerous mineral and pigment. Its gorgeous red color should be admired from a distance, or the cinnabar should be used with caution.