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A groundbreaking underwater archaeological discovery has confirmed a 2,300-year-old mystery described by Aristotle: an ancient copper mine submerged beneath the waters near Istanbul’s Heybeliada island may have supplied prestigious bronze workshops in ancient Greece. This remarkable find connects the philosopher’s historical writings with physical evidence, revealing an extraordinary trade network that linked skilled divers, rare materials, and the celebrated sculptors of classical antiquity, reports Turkiye Today.
Bust of Aristotle, the ancient Greek philosopher whose writings led to the discovery. (Public Domain)
Ancient Texts Meet Modern Discovery
In his work “De Mirabilibus Auscultationibus” (On Marvelous Things Heard), Aristotle documented a peculiar mining operation near what is now Heybeliada, one of Istanbul’s Princes’ Islands. The Greek philosopher recorded that divers extracted copper from a mine lying under two fathoms of water – approximately 3.6 meters (12 ft) below the surface. This copper, he noted, was used to create statues in the Temple of Apollo at Sicyon and monuments at Pheneus, including dedications attributed to Heracles. What made this account extraordinary was not just the underwater mining operation itself, but Aristotle’s observation that the copper possessed remarkable properties, including supposed benefits for eye health and the ability to improve the vision of those who worked with it.
For centuries, scholars debated whether Aristotle’s account represented factual observation or mythological embellishment. The balance shifted decisively in 2018 when archaeologist Associate Professor Ahmet Bilir from Duzce University led an underwater survey team to Camlimani Bay on the coast of Heybeliada. During their 15-day expedition, researchers identified clear evidence of ancient copper mining operations at depths matching Aristotle’s description. The discovery included visible green copper oxidation staining on the seabed, ore samples, and indications of systematic extraction dating to the Late Classical Period of ancient Greece.
Seabed at a depth of approximately four meters in Camlimani Bay, Heybeliada, Istanbul, Türkiye, showing green copper patches among natural rock formations. (Photo via Assoc. Prof. Ahmet Bilir/Tina)
The Prestigious Trade in “Diver’s Copper”
According to Professor Bilir’s research, this underwater copper held special status in the ancient world, known as “khalkon kolymbeten” or “diver’s copper.” Unlike ordinary copper extracted from land-based mines, this material commanded premium prices and occupied a unique position in ancient Mediterranean trade networks. The copper from Heybeliada was not mass-produced for general consumption but rather constituted what Bilir describes as a “niche market product” intended for elite artistic and religious clientele.
The symbolic value of diver’s copper extended beyond its material properties. In ancient Greek religious culture, offerings to the gods were judged not merely by their intrinsic worth but by the effort and difficulty required to obtain them. Copper extracted from beneath the waves demanded exceptional skill, courage, and technical knowledge. Ancient divers working at depths of several meters would have faced significant challenges, particularly given the limitations of ancient diving technology. Aristotle himself documented early diving apparatus, and the divers of Heybeliada would have used simple breathing devices and relied on extended breath-holding capabilities to extract ore from the submerged mine.
Roman Bronze Copy of Greek Hercules (Herakles) Original by Lysippos. (Gary Todd/CC0)
From Istanbul’s Waters to Greece’s Greatest Sculptors
The most compelling aspect of this discovery lies in its connection to one of antiquity’s most celebrated artists. Historical evidence suggests that copper from Heybeliada was shipped to Sicyon, home to a renowned sculpture school that trained masters including Lysippos, the official sculptor of Alexander the Great. Lysippos revolutionized Greek sculpture with his naturalistic style and innovative proportions, creating works that became defining images of the Hellenistic period. Ancient sources indicate that Alexander himself decreed that only Lysippos could create his portraits in bronze, elevating the sculptor to unparalleled prominence.
The connection between Heybeliada’s underwater mine and Lysippos’ workshop represents more than a simple supply chain. According to Bilir’s analysis, the diver’s copper may have been among the materials used for statues dedicated to the Temple of Apollo at Sicyon. These weren’t ordinary bronze statues but sacred offerings intended to honor the gods with the finest materials available. The fact that such copper came from underwater mining operations would have enhanced its spiritual significance, making it particularly appropriate for religious dedications.
Copper ore samples retrieved from the underwater site in Camlimani Bay
Source: Türkiye Today
Economic and Cultural Significance
The underwater copper mine at Heybeliada functioned within a sophisticated ancient economy that valued specialized materials and recognized different grades of metallic resources. While copper mining was widespread across the ancient Mediterranean, the submarine deposits near Istanbul represented a unique and premium source. Bilir emphasizes that this operation contributed significantly to Heybeliada’s local economy in antiquity, though the underwater mine maintained its special status separate from more conventional mining activities in the region.
The technical achievement represented by this mining operation should not be underestimated. Ancient divers working in Camlimani Bay would have needed to descend repeatedly to extract ore from beneath several meters of water, transport it to the surface, and maintain consistent production. Aristotle’s account mentions that workers at the mine experienced improved eyesight, a claim that may reflect the copper’s use in ancient medicine rather than supernatural properties. Ancient Greek and Roman physicians did indeed use copper compounds, including copper sulfate and “flower of copper,” in various eye treatments.
The verification of Aristotle’s account through archaeological evidence also validates ancient texts as valuable sources for understanding historical technology and trade. While classical writings must always be evaluated critically, this discovery demonstrates that seemingly remarkable ancient accounts can sometimes prove to be accurate observations of real practices. The philosopher’s attention to unusual details about underwater mining, copper extraction, and the material’s subsequent use has been vindicated by modern underwater archaeology, bridging 2,300 years between ancient observation and contemporary confirmation.
Top image: Underwater photograph showing oxidized copper traces in Camlimani Bay, Heybeliada, where researchers observed green copper staining consistent with ancient copper ore exposure. Source: Türkiye Today / Assoc. Prof. Ahmet Bilir
By Gary Manners
References
Bilir, A. 2020. Aristotle’s Underwater Copper Mine at Heybeliada and Reflections of Diver’s Copper on Late Classical Sculpture. Available at: https://www.researchgate.net/publication/338571628
De Mirabilibus Auscultationibus. c. 300 BC. Available at: https://en.wikipedia.org/wiki/On_Marvellous_Things_Heard
Türkiye Today. 2025. Could Aristotle’s ‘diver’s copper’ have come from Istanbul’s waters? New evidence points to yes. Available at: https://www.turkiyetoday.com/culture/could-aristotles-divers-copper-have-come-from-istanbuls-waters-new-evidence-points-to-3210058
