TR
EN
Glossary
Introduction
Glossary
Reading List
Wetlands
Wetness
Sea Snotting
Istanbul Coastline Atlas
Speculative Fictions
Extraction
Deniz Karakaş

Just before entering the US, you are asked to fill out a customs form that includes a curious question that still puzzles me: “Are you bringing soil?”—as if soil were something dangerous or precious, something that must be declared.1 But yes, soils have long traveled across borders.2 Perhaps the most famous of all was the earth of the north Aegean island of Lemnos, which circulated widely across the Levant and Europe for centuries. This was, of course, not an ordinary earth. Known in antiquity as terra Lemnia or terra sigillata, meaning “sealed earth,” Greek and Roman authors thought it possessed healing and miraculous powers.3 Arab physicians referred to it as ṭīn al-buḥayra, meaning “earth of the little marsh,”4 and stretching back to antiquity, some later manuscript copies of Dioscorides’ De materia medica (1st century CE) mentioned a “marshy spot” when talking about the Lemnian earth.5 Were they referring to the island’s salt marsh-type wetlands6 in the northeastern part (like the Aliki salt lagoon) or to shallow lakes (like Chortarolimni), where the earth might have been dug up during elutriation?7 Hard to know. But following the Ottoman seizure of the island in 1456, new distributions of power reshaped both extraction and circulation.8 Referred to in Ottoman sources as ṭīn-i maḫtūm (or ṭıyn-ı maḫtūm), Lemnian earth came to embody the inextricable ties between knowledge and hybrid sacred-bureaucratic economy in which ritual, medicine, and state authority intersected.9

Artists contributed to this, too. In French cosmographer André Thévet’s 1575 La Cosmographie universelle, an engraving of Lemnos illustrates the ceremony and extraction practices in Ottoman times.10 The scene depicts the Orthodox Feast of the Transfiguration, with a procession beginning at the church of the Saviour (Sotira) shown above Mount Vtran and descending toward a crowd arranged along terraced embankments. Poles topped with cross-like finials mark the gathering and direct attention toward a figure down in a small, shallow pit. Numerous figures carry baskets and sacks, work the ground, and lead pack animals, while a turbaned rider on horseback—likely representing the local administrative or military governor (ṣubāşı) charged with overseeing the extraction—stands nearby. Slightly to the center, a timber building with narrow openings and a steep pitched roof is shown in use, most likely a storehouse or processing facility. Worn-out paths register what might be called “the accumulated imprint of countless journeys,” as camels, carts, and boats carry off the sacks of sealed earth through sparsely vegetated, marshy lowlands toward the port in the foreground. The image thus reinforces what terra Lemnia is all about. The ceremonial digging, alternations of shaping the ground year after year, shipment, and human labor together appear to weave deep-time processes into everyday life.

Lemnos (after André Thévet, La Cosmographie universelle, 1575)
Source: Bibliothèque nationale de France

However, there was also a scarcity in the markets and a cost burden.11 Arthur MacGregor, former curator at the Ashmolean Museum, has vividly described how other deposits and patches of clay were identified and exploited across Central and Western Europe during the late 16th and 17th centuries.12 With competition came validation and new sorts of knowledge claims. Like the segregation of clay within soil, the segregation of places of origin, veins, strata, and the virtues of certain earths led to the emergence of counterfeits, making credentials necessary.13 Differentiated and renewed claims consigned those laborers who extracted the earth into anonymity; images drove the lucrative trade.14 These dynamics are evident in the cabinet of curiosities of the 17th-century Danish physician, linguist, and natural philosopher Ole Worm.

Left: Pen-and-ink drawing showing six different pieces of sealed medicinal earth known as terra sigillata; right: Pen-and-ink drawing showing all seventeen images of sealed medicinal earth known as terra sigillata (after Worm’s Museum Wormianum, 1655)
Source: Wellcome Collection

In Worm’s catalogue, alongside Lemnian examples bearing Ottoman inscriptions are troches stamped with a double-headed eagle (Erlach, Switzerland), a fleur-de-lis on the base (Blois, France), and another depicting a hermit kneeling in adoration of a crucifix in a cave (from Malta, perhaps intended to evoke the sacred earth of the cave believed to have sheltered the Holy Family in Bethlehem).15 The patches of clay are, in a sense, “migrants.”16 What appears as a static, permanent geological container proves to be contingent and in motion, shaped by the silent desire of survival and security as much as divergent practices of extraction and sovereignty imposed upon it. This process reminds me of a recent roundtable discussion on extractivism, stating that “conceptualizing ‘supply’ as a provision filling a void or lack produces a chain of extractivism.”17

1 I guess I am not alone who has noticed this. Leanne Wijnsma, an artist and curator, has made a similar observation in one of her Instagram posts.
2 See “Borders.”
3 For a comprehensive overview of post-medieval literature on the Lemnian earth, covering its healing properties, how it’s extracted, and the rituals linked to it, and including what notable authors wrote, such as Joos van Ghistele (1485), Piri Reis (1521), Pierre Belon (1546–47), and Stefano Albacario (1562), see F. W. Hasluck and M. M., Hasluck, “Terra Lemnia,” Annual of the British School at Athens, 1929, pp. 671–688; Julian Raby, “Terra Lemnia and the Potteries of the Golden Horn,” Bosphorus: Essays in Honour of Cyril Mango, eds. Euthymiades et al., Amsterdam: Adolf M. Hakkert, 1995, pp. 305-341, plates 1-3; and Heath W. Lowry, On Beşinci Yüzyıl Osmanlı Gerçekleri: Limnos (Limni) Adasında Yaşam, trans. M. Alper Öztürk, Istanbul: Bahçeşehir University Publishing, 2013.
4 W. Schmucker, Die pflanzliche und mineralische Materia medica im Firdaus al-Hikma des Tabari, Bonn: Bonner Orientalische Studien, 1969, p. 293; cited in Raby, “Terra Lemnia,” p. 310n24.
5 Evidence of its pre-15th-century knowledge also appears in an illustration from an Arabic copy of Dioscorides’ De materia medica (1224 CE), depicting the gathering of the Lemnian clay by two men. Accessed: 12.11.2025, asia-archive.si.edu. For more details, see Esin Atıl, Art of the Arab World, Washington: Smithsonian Institution, 1975, cat. no. 22, p. 57.
6 See “Wetlands.”
7 Fwtw Konsola, “Lake Alyki and Chortarolimni: The Important Wetlands of Lemnos Island,” Lemnos Nature, November 4, 2017. Accessed: 12.11.2025, www.lemnosnature.gr.
8 Back in Ancient Greek times, the island was called Lemnos (Λῆμος) as noted by A. H. De Groot in “Limni,” Encyclopaedia of Islam New Edition Online, ed. P. J. Bearman, Brill, 2012. Accessed: 12.11.2025, doi.org. In Ottoman documents, the island was referred to as Limnos or Limni. Lowry, On Beşinci Yüzyıl Osmanlı Gerçekleri, pp. xx–xxiv.
9 The island came under definitive Ottoman rule in 1479. Historians today point out that the Ottomans were particularly keen on keeping Lemnos because of its rare medicinal clay, terra sigillata. During Ottoman times, physicians used this soil, shaped into tablets and stamped, for its medicinal powers, including the treatment of plague, which was a major issue in the Ottoman capital in the 15th and 16th centuries and that’s when the term ṭīn-i maḫtūm became official. On the rediscovery of Lemnian earth by the Ottomans, see Henryk Jaronowski, “‘An Earth by Any Other Name’: Pre-Ottoman Sources and Names for Lemnian Earth,” Helenika, Vol. 58, No. 1, 2008, pp. 48–70 and Yasemin Demircan, “Tıyn-ı Mahtûm: Akdeniz Dünyasının Mucize Toprağı,” Acta Turcica, No. 1, January 2012, pp. 281–295. As Demircan shows, the production of this mineral was primarily controlled by bureaucratic means rather than being driven by market forces. The island was taken over by Greece in 1912.
10 André Thévet, La Cosmographie universelle, Vol. II, Paris: Guillaume Chandiere, 1575, p. 805. Accessed: 11.01.2026, gallica.bnf.fr. It contains some interesting points that were not uncommon at that time. F. W. Hasluck argued that Thévet had never set foot on the island and so called him a plagiarist. This suggests that it was an imaginary view of the island and he probably relied on earlier sources to help the artist. For more on this topic, see F. W. Hasluck, “Thevet’s Grande Insulaire and his Travels in the Levant,” Annual of the British School at Athens, No. 20, 1913–1914, pp. 59–69.
11 For further discussion on new alternatives, see Karl H. Dannenfeldt, “The introduction of a new sixteenth century drug: terra Silesiaca,” Medical History, Vol. 28, No. 2, 1984, pp. 174–188.
12 Arthur MacGregor, “Medicinal terra sigillata: A Historical, Geographical and Typological Review,” Geological Society of London Special Publications, Vol. 375, No. 1, 2013, pp. 113–136.
13 See “Segregation.” For more recent scientific investigations on the physical and chemical properties of Lemnian earth and its possible health benefits (like the presence of fungi and bacteria), see Effie Photos-Jones and Allan J. Hall, “Lemnian Earth, Alum and Astringency: A Field-Based Approach,” Medicine and Healing in the Ancient Mediterranean, ed. Demetrios Michaelides, Oxford: Oxbow Books, 2014, pp. 183–189.
14 Indeed, MacGregor further points out that a lot of what we know about terra sigillata comes from the illustrated catalogues made by collectors of curiosities back in the day. MacGregor, “Medicinal terra sigillata,” pp. 116–118.
15 Ole Worm, Museum Wormianum, seu, Historia rerum rariorum: tam naturalium, quam artificialium, tam domesticarum, quam exoticarum, quae Hafniae Danorum in aedibus authoris servantur, Lugduni Batavorum: Apud Iohannem Elsevirium, 1655, pp. 3, 9-15. Accessed: 05.01.2026, archive.org.
16 Hanna Rullmann and Faiza Ahmad Khan, Habitat 2190, 2019; Interview by Elinor Morgan on Habitat 2190. Accessed: 29.05.2025, www.vdrome.org.
17 Nina Wexelblatt, Imani Jacqueline Brown, Charlotte Malterre-Barthes, Thea Riofrancos, and B. Jack Hanly, “Round Table: Landscapes and Logics of Extractivism,” Thresholds, No. 49, 2021, pp. 21–28.