Cinnabar, mercury(II) sulphide (HgS), is a very durable, glossy red powder that was first extracted naturally and later made from mercury and sulphur. Natural and chemically derived cinnabar was one of the most sought-after dyes used between antiquity and the 19th century, especially in painting, cosmetics and dyeing fabrics.

Picture 1: Artificial cinnabar known as vermillion, was made from mercury (Hg) and sulphur (S).
Photo: Jani Peternelj, Photo Archives of CUDHg Idrija

Picture 2: Rich cinnabar ore.
Photo: Jani Peternelj, Photo Archives of CUDHg Idrija

In prehistoric times, natural cinnabar was extracted by grinding very rich cinnabar ore. The Chinese were probably the first to produce artificial cinnabar by fusing mercury and sulphur, as early as the 4th BC. In the 3rd century BC, the Greek alchemist Zosimus of Panopolis wrote about it. The Greek philosopher Theophrastus of Erez (371–286 BC) described the process in the first scientific book on minerals, De Lapidibus. The knowledge and experience to make cinnabar was brought to Europe by the Arabs in the 8th and 9th centuries. Since then, cinnabar has been produced in various parts of Europe, most of it and of the highest quality by the Venetians and the Dutch.

the use and importance of cinnabar
over the centuries

Man knew and used cinnabar long before mercury. It was used as a colour, as a commodity in trade, or just as a great treasure. The earliest use dates back to the Neolithic period, when cinnabar paint was found in cave paintings dating back to around 30,000 BC in what is now Spain and France.

The earliest documented use of cinnabar dates back to 8000–7000 BC and was found in paintings at the Catalhoyuk settlement in present-day Turkey. This large Neolithic settlement in southern Anatolia, southeast of the present-day city of Konya, had a population of 5 000 to 7 000. Paintings of animals (bison and deer) and people have been found on the inner and outer walls of the clay huts. It is known that the ancient peoples had a special, almost religious, attitude towards the cinnabar.

Picture 3: A deer Picture from a wall painting in the Neolithic settlement of Catalhoyuk in present-day
Turkey (8000–7000 BC) – the earliest documented use of the cinnabar. Source: Diomedia

In Spurgola, near Rome, human skulls painted with cinnabar were discovered in a tomb dating from the Younger Stone Age (7000–5000 BC). The same is true of the necropolis of Vilafratti near Palermo in Sicily. In the ruins of the Mayan city of Palenque in Mexico, a sarcophagus dating from 700–600 BC, called the "Tomb of the Red Queen", was found. The body and the objects in the sarcophagus were covered with a light red cinnabar paint.

In China, from the earliest times, cinnabar was the colour of blood and therefore the colour of life. It was called 'dragon's blood' and used in immortality pills. Cinnabar was an ingredient in many preparations for heart disease and to promote blood circulation. The old Chinese word for cinnabar was tan-sha. 'Tan' was the great mystery word in Chinese alchemy and mineralogy.

One of the oldest uses of cinnabar was in the preparation of red ink. In Anyang County, Hunan Province, China, human bones dating from 1751–1112 BC have been found inscribed with a persistent red cinnabar ink, allowing the reconstruction of ancient Chinese history. In the Chou dynasty (770–265 BC), bone replaced silk as a writing surface. Cinnabar ink, however, remained in use. (Kavčič, 2008)

Picture 4: Human bones inscribed with cinnabar ink in China from the Shang-Yin dynasty 1751–1112 BC. Source: Diomedia.

The Greek historian Herodotus (490–425 BC) writes that in ancient times warships were painted with a red colour called 'miltos'. The historian Johannes Hasebroek notes that 'miltos' was used as a coating against water pests, suggesting that it was not iron oxide but the more effective Cinnabar paint.

In Pompeii, as early as the 1st century BC, the Romans used cinnabar to paint palaces and to paint faces and bodies on triumphal marches. They added it to sealing waxes, used it to make ink, painted statues of their deities and used it to make paints.

Picture 5: Paintings of the palace at Pompeii with cinnabar. Photo: Miha Jeršek

From the 16th century onwards, the Venetians and the Dutch used cinnabar to dye fabrics and ships, and in cosmetics for make-up and hair dye. The great European painters used cinnabar as their main red colour from the Renaissance until the 20th century.

venetians, makers of the finest cinnabar

The Venetians were known as the oldest and best producers of the purest and finest cinnabar. After them, the Dutch mastered the manufacture of cinnabar. One, like the others, made it in their own way. The secret of the artificial production of fine cinnabar was carefully kept to themselves and not divulged to anyone. For centuries, the Idrians, who also produced cinnabar, have tried in vain to discover the secret of the Venetian and Dutch production of fine cinnabar. Other mercury mines did not usually produce artificial cinnabar, but only natural cinnabar. The Idrija mine was an exception in this respect.

the production of cinnabar in idrija represents the first chemical industry in slovenia

Cinnabar was produced in Idrija (Slovenia) in two periods: from 1490 to 1658 and from 1782 to 1915. 8 800 tonnes of cinnabar were produced in just over 300 years.

the first period of cinnabar production in idrija 1490–1658

In the first years after the discovery of mercury, only natural cinnabar was produced in Idrija by grinding the finest and purest pieces of cinnabar ore. Natural cinnabar had many impurities and could not compete with artificial cinnabar, of which the Venetians and the Dutch were the greatest masters. As early as the first half of the 16th century, cinnabar was produced in special furnaces. Mercury mixed with powdered sulphur was filled into retorts and heated until cinnabar was formed. From the beginning of the mine's operation in 1490 until 1509, when Idrija fell under Venetian administration, cinnabar production was high. The price of cinnabar was higher than that of mercury during this period, and natural cinnabar was extracted by grinding the rich cinnabar ore.

At the end of the 16th century, a cinnabar kiln was built at Grablje on the Idrijca. At that time, cinnabar was already being extracted chemically using a dry process. The mercury was added to powdered molten sulphur, the mass was placed in vats, which were rotated by mechanical means for several hours, and then the well-mixed mixture was calcined burned in the calciner vatsclay retorts forretorts for a sufficient time for the sulphur to combine with the mercury to form cinnabar. The firing burning of cinnabar was carried out indoors, whereas mercury cinnabar ore was firedburned inburned in clay retorts in open woods during this period.

The raw materials and the process of making cinnabar, from the extraction of the mercury, the import of sulphur from Italy, the preparation and supply of the wood for burning the mercury into cinnabar and the supply of the clay vessels in which the mercury was burnt into cinnabar, were very expensive. The production of cinnabar in Idrija depended on the interest and demand for the product from traders.

In the first period from 1490 to 1658, 1500 tonnes of cinnabar were produced and exported to Venice, Italy, the Levant, Germany and Spain. During this period, Villach played an important role in the mercury and cinnabar trade. In the middle of the 17th century, the production of cinnabar in Idrija fell sharply due to the costs and ceased in 1658. (Verbič, 1971).

emperor joseph ii advocates
the resumption of cinnabar production

Efforts to restore cinnabar production in Idrija lasted 124 years. After the cessation of cinnabar production in 1658, the Viennese Government made constant efforts to restore cinnabar production in Idrija by improving the extraction process and reducing costs. This is why they invited sublimators (goldsmiths, alchemists) from Venice and Graz to experiment with the production of cinnabar.

Balthasar Hacquet, the famous mine surgeon and naturalist, also worked hard to restore cinnabar production. When he left Idrija for Ljubljana in 1773, the Austrian Emperor Joseph II visited him and discussed with him for an hour and a half. Hacquet explained to him that the Idrija mine could do better business if cinnabar production was restarted. In his biography, he says that he achieved then what he could not have done before by propagandising the public for 12 years. He calls Emperor Joseph II. the only great man of the Austrian Imperial House! (Mohorič,1960)

Fig. 6: Balthaszar Hacquet (1739/40–1815), naturalist, polymath, surgeon, university professor, from 1766–1773 he worked in Idrija (source).

Thus, in 1782, at the initiative of Balthasar Hacquet, a cinnabar factory was built on the right bank of the Idrijca River, where a hundred years later the distillery was also moved.

the new cinnabar factory was built in 1782

Under the leadership of the master distiller and innovator Ignaz von Passetzky, a modern cinnabar factory was built on the right bank of the Idrijcka River in 1782. The standard dry process and the more technologically demanding wet process were used to produce cinnabar, although the wet process was abandoned because it was too costly. Several experts, especially of Czech origin, continued their research. At the end of the 19th century, Bohemia had the most developed chemical industry in the Austro-Hungarian Empire and therefore also the experts with the knowledge they brought to Idrija. In the 1880s, during the tenure of the mine's director, Marko Vincenc Lipold, successful experiments led to the restart of the production of cinnabar, including by the wet process. At the same time, the factory was thoroughly renovated and modernised.

Picture 7: The cinnabar factory as depicted by Goldstein in the mid-19th century. Photo Archives of National museum of Slovenia, Ljubljana

Idrija's cinnabar was in great demand in the late 18th and early 19th centuries. It was sold in pieces or ground into a fine powder called vermillion.

the cinnabar works in the 20th century

In 1918, at the time of the dissolution of the Austro-Hungarian Empire, the cinematographic workscinnabar factory had a surface area of around 1 000 m2. Sixteen rooms housed the dry and wet cinnabareur production facilities. The last 400 kg of product were packed in 1922. Since then, no more cinnabar has been produced in Idrija. The high-quality cinnabar dye was replaced by the much cheaper aniline dyes at the beginning of the 20th century, due to its lower price and lower toxicity.

Picture 8: The preserved wooden structure on which the millstone was attached in the factory cinnabar mill in Idrija. Photo: Bogdan Kladnik, Photo Archives of CUDHg Idrija

visitor centre at the Hg Smelting plant

Since the beginning of February 2017, a permanent exhibition on mercury called "From Ore to Mercury drops" has been on display in Idrija at the Idrija Mercury Mine Smelting Plant, where cinnabar is also featured. The Idrija City Museum, Gewerkenegg Castle, displays preserved objects and equipment from the 'Cinobrarna' (cinnabar factory).

Picture 9: The permanent exhibition at the Hg Smelting Plant in Idrija.
Photo: Stane Jeršič, Photo Archives of CUDHg Idrija

Picture 10: Mercury
Photo: Matej Peternelj, Photo Archives of CUDHg Idrija

Web sources:

https://en.wikipedia.org/wiki/Vermilion
https://www.thoughtco.com/cinnabar-the-ancient-pigment-of-mercury-170556
https://en.wikipedia.org/wiki/Chinese_alchemy
https://en.wikipedia.org/wiki/Tales_of_Old_Japan

Martina Peljhan is geoloist and professional assistant at Idrija Mercury Heritage Management Centre