Cinnabar is a bright red mineral composed of mercury sulfide that has been used as a pigment, a ceremonial material, and a medicinal ingredient for over 10,000 years. Its most recognizable role is as the source of the vivid red pigment known as vermilion, but it also has a long history in Traditional Chinese Medicine and Ayurvedic practice. Today, its uses are more limited due to well-documented concerns about mercury toxicity.
Cinnabar as a Pigment and Decorative Material
Cinnabar’s most widespread use throughout history has been as a red pigment. The mineral itself is called cinnabar, while the pigment made from it is called vermilion. Chemically they are the same substance, but the terms distinguish the raw mineral from the processed color. Cinnabar has been mined for this purpose since at least the 10th millennium B.C., making it one of the oldest pigments in human history.
The list of cultures that prized this red mineral is remarkably long. Neolithic peoples in Anatolia, China, Spain, Syria, and the Galilee region applied it to skulls and bones during burial rituals. The Shang dynasty in China and the Olmecs in Mexico were using it by the first and second millennia B.C. Iron Age cultures on the Iberian Peninsula incorporated it into jewelry, and the Achaemenid Persian Empire used cinnabar as a gemstone bedding, placing it beneath translucent carnelian stone to amplify the stone’s reddish glow.
Romans considered cinnabar sacred and used the pigment during triumphal processions. The ancient Greeks knew it well too. The botanist Theophrastus described how to extract it in the fourth century B.C., though Greek objects at the Metropolitan Museum of Art show traces of cinnabar from significantly earlier periods. Early Cycladic marble sculptures, once thought to be plain white, were found by conservators to have been decorated with cinnabar paint.
In East Asia, cinnabar was mixed into urushiol sap to create the deep red lacquerwork that became iconic in Chinese and Japanese decorative arts. In South America, the Inca and pre-Inca cultures used cinnabar on ceremonial drinking vessels called qeros, likely sourcing the mineral from Huancavelica, Peru, the largest mercury mine in the Americas. By the 12th century, vermilion was being used on carved stucco, wall paintings, and terracotta friezes in Nishapur, Iran, sometimes layered over a bright orange-red lead base in egg-tempera medium.
Synthetic Vermilion
People eventually figured out how to make cinnabar’s pigment without mining it. A Greek alchemist named Zosima of Panopolis, living in Upper Egypt, recorded a process for synthesizing vermilion by at least the fourth century A.D. A Persian alchemist, Jabir ibn Hayyan, described a similar method around the eighth century. The technique, which may have originated in China as early as the fourth century B.C., involved heating mercury and sulfur together in a sealed container. This “dry method” produced a synthetic pigment chemically identical to the natural mineral, and it eventually made vermilion more widely available to artists and craftspeople.
Uses in Traditional Chinese Medicine
In Traditional Chinese Medicine (TCM), cinnabar is known as Zhu Sha and has been used as a medicinal ingredient for thousands of years. The Chinese Pharmacopoeia describes it as a mineral containing at least 96% mercury sulfide and lists its traditional functions: calming the mind, relieving restlessness, improving eyesight, and clearing what TCM practitioners call “heart fire.” It is a core ingredient in several well-known Chinese formulas, including Zhusha Anshen Pill and Baizi Yangxin Pill, both prescribed for anxiety and insomnia.
Modern pharmacological research has found that cinnabar preparations can produce measurable anti-anxiety and sedative effects. Studies have also identified antioxidant and neuroprotective properties in certain formulations, and compound preparations containing cinnabar have been used in the treatment of insomnia, anxiety disorders, brain trauma, stroke, and neuroinflammation. These effects come from carefully controlled doses within multi-ingredient formulas, not from cinnabar taken on its own in large amounts.
Uses in Ayurvedic Medicine
In the Ayurvedic tradition, cinnabar is called Hingula and plays an important role in Rasashastra, the branch of Ayurveda focused on mineral-based medicines. Purified Hingula is considered useful for eye diseases and is said to balance all three doshas (the body’s fundamental energies in Ayurvedic theory). Practitioners have used it in formulations targeting liver and pancreatic disorders, rheumatoid arthritis, diabetes, fever, and skin diseases including leprosy.
Cinnabar also serves a more specialized function in Ayurvedic mineral processing. It is the primary natural source of mercury, and the mercury extracted from cinnabar (called Hingulottha Parada) is considered high quality for use in further preparations. It also plays a role in the incineration procedures used to process gold, silver, and other metals into therapeutic forms.
Mercury Toxicity and Safety Concerns
The elephant in the room with any discussion of cinnabar is mercury. Cinnabar contains over 95% mercury sulfide, and while mercury sulfide is far less bioavailable than other forms of mercury, it is not harmless. The body absorbs roughly 5,000 times less mercury from cinnabar than from organic mercury compounds like methylmercury, which is why traditional medical systems considered it relatively safe. But “relatively” is doing a lot of work in that sentence.
Animal studies have shown that high doses of cinnabar (1 gram per kilogram of body weight per day for one to two weeks) cause clear neurotoxic effects, including problems with balance, hearing, memory, and muscle function. More concerning, long-term exposure at much lower doses (10 milligrams per kilogram per day for more than 77 consecutive days) also produced neurotoxic effects linked to significant mercury accumulation in the brain. Research on offspring mice found that maternal exposure to low doses of cinnabar caused neurological and hearing-related damage in the young, suggesting the risks may extend to developing children.
The Chinese Pharmacopoeia sets strict maximum daily dosage limits for cinnabar in medicinal formulas, and the mineral is always supposed to undergo specific processing before use. Even so, the arsenic and mercury content of these mineral medicines requires careful toxicological assessment, particularly for chronic exposure and organ-specific effects. Several countries outside of Asia restrict or ban the sale of cinnabar-containing medicines entirely.
Environmental Legacy of Cinnabar Mining
Cinnabar mining has left lasting environmental damage in many regions. Abandoned mining sites in southwestern Spain, for instance, show elevated mercury levels in both soil and plants long after mining operations ceased. Mercury released from cinnabar mining doesn’t stay put. It enters water systems, converts to methylmercury in aquatic environments, and accumulates up the food chain. Historic mining regions in Spain, Slovenia, Peru, and parts of China and California continue to deal with mercury contamination as an environmental and public health concern decades or even centuries after the mines closed.