002.271.Idrija

Idrija Mercury Heritage Management Center, Bazoviška 2, SI-5280 Idrija

Public

Republic of Slovenia

/

Mine, Smelting

The cay vessel for burning (retorta) consists of two parts, namely of a washer and a vessel. The larger upper part is in an elongated shape. The last quarter of the described part of the vessel for burning has a semicircular edge designed on it (ring). From this part on, the vessel is slightly narrowed and continues in the second part of the vessel which is in a shape of a smaller vessel. The vessel is axially symmetrical and pointed. The diameter of the bottom part of the vessel is narrower. This part has a mounted washer. The edge of the vessel fits nicely on the top edge of the vessel. The clay vessel for burning is light brown, with visible traces of soot.

Length 32 cm, width 10 cm, height 10 cm.

Pottery clay

The middle of the 16th century – the first half of the 17th century.

The Cinnabar Ore Factory of the Idrija Mercury Mine.

Burning cinnabar ore in clay vessels upgraded the original burning in piles. It came into use in the 16th century and was in use for the next 150 years. According to the mining expert Georgius Agricola’s (De re metallica) description, they filled approximately 1,000 jugs with the crushed ore (approximately 1.5 kg). Then the turned jug was connected with another clay vessel (recipient). The gap between the vessels was glued with clay. Furthermore, the recipient was filled with sand or soil. They piled logs on the vessel that stuck out of the ground and burned it. Under the influence of heat (around 600 °C, 12–24 hours) the ore in the upper vessels started to decompose into mercury and sulfuric vapours. After cooling, the metallic mercury was collected in the bottom vessel. During the burning, a large amount of mercury got lost. The clay vessels were not used more than three times, as they often cracked during the burning. In Idrija, they annually had 50–60,000 vessels in stock.

The clay vessel for burning is being preserved, secured and presented as important mining heritage of Idrija with exceptional universal values. Visitors can view it within the permanent museum display “From Ore to Mercury Drops” in the renovated venue of the Hg Smelting Plant. The path of the ore excavated in the Idrija Mine is presented from the transport station at Joseph’s shaft to the sorting, crushing and burning devices in the Smelting Plant. The development of the burning furnaces throughout the centuries is presented, which revives the memory of the 500 years of hard work of Idrian smelters, who were improving the methods of ore smelting from generation to generation. The steel flask is a part of the presentation that presents the method of mercury storing and transporting.

Burning plants in the surroundings of Idrija (according to the residues, 20 locations were evidenced).

Hg Smelting Plant (From Ore to Mercury Drops), Arkova 50, SI-5280 Idrija.

The object is properly preserved. Additional interventions are not necessary. Security of the premises is taken care of.

good

Regular seasonal maintenance.

- CUDHg Inventory Book;
- Kavčič, Ivica. Živo srebro: Zgodovina idrijskega žgalništva. Založba Bogataj, Idrija, 2008;
- Kavčič, Ivica. Proizvodnja živosrebrovih spojin pri idrijskem rudniku skozi stoletja. Idrijski razgledi, 61/2, 2016, p. 60–76.

Mestni muzej Idrija

Miha Kosmač

12. 3. 2018

Never