Lavrion Minerals

The history of Lavrion mines, lost to the depths of the time, is directly connected with the history of Greece. Lavrion took its name after the Greek word “lavra” which means narrow passage or tunnel describing the characteristics of mining galleries. The first underground excavations began around 3000 BC establishing Lavrion mines as the oldest in Europe. However, the production of silver was limited until 483 BC (the period of Greco-Persian wars), when the rich deposits of Maronia (present day Agios Konstantinos) were discovered and the greatest mining period began.

The silver production was so high that the historians of the Classical Period wrote: “the silver is flowing like spring water”. The Lavrion silver mines soon became the principal source of wealth for the Athenian State. Hundreds of tons of silver that had been initially stored in the Parthenon treasury were liquefied in order to erect several of the city’s architectural monuments. The construction of an enormous war and trade fleet with a hegemonic presence in the Eastern Mediterranean region was financed. Fine Arts and Sciences (philosophy, mathematics, astronomy, drama, history etc.) flourished. The tetradrachmon, the currency of the Athenian State, which was constructed from the silver, became the dominant currency of the ancient world.

The decline of the mines came during the Peloponnesian War, a 30 year civil war between Athens and Sparta. In 413 BC, the Spartans captured Lavrion and the excavations in the mines ceased. Some decades later, Athenian economy recovered and silver production recommenced. However, Macedonia under Philip II (Alexander’s father) was now the dominant power in the Hellenic region and the silver Athenian tetradrachmon was surpassed by the golden Macedonian drachma. The works in Lavrion mines will continue, but with decreased rates, until the first Byzantine Period (6th century AC).

At this point, we must mention that the silver and lead extraction from galena ore in the ancient times was a technological miracle. The process had four stages:

• The galena ore (which contained the silver) was enriched in washing units by using water under pressure in order to remove the light and poor in metal parts of the ore.
• The enriched galena which is a lead sulphide (PbS) + silver (Ag) was converted to the oxide form (PbO + Ag) by roasting (in metallurgy this process is called reduction roasting).
• PbO + Ag chemical compound (which is called litharge) was directed into a furnace, where it melted with carbon and produced a PbAg alloy (reduction melting process).
• The Pb-Ag alloy was next placed into a fireproof ceramic cup. The cup was heated in a specially constructed furnace were air was blowing under pressure. At 900 the alloy melted and Lead (Pb) was oxidizing while silver (Ag) was not oxidizing. Then the alloy formed two separate layers, a heavy one containing silver in the bottom of the cup and a lighter containing litharge in the top. Litharge was removing and the process was continuing until the silver in the bottom was pure (over 99%). The precious metal was then ready for coins construction.

The abovementioned metallurgical process of ancient Greek metallurgists is followed, with no essential changes, until nowadays for silver production. Its efficiency was slightly improved in the late decades of 19th century by the discovery of flotation method for the ore enrichment and the Water-Jacket furnace for reduction melting. Professor Constantine Konofagos, in his significant book “The ancient Lavrion”, describes in detail the metallurgical process of silver production in the ancient period.

Lavrion area between the 6th and 19th century was abandoned, loosing all of its old glory. It was 1859 when the Greek metallurgist Andreas Cordellas was sent by the Greek government in Lavrion to examine the possibility of reopening the mines after a lapse of centuries. Cordellas detected the presence of extensive ancient mining residues which could produce large quantities of lead and zinc (zinc was an unknown metal in ancient world while lead had limited applications and was produced in small quantities). Immediately, two mining companies were founded: The Greek Company which was exploiting the ancient ore residues and the French Company (led by the French-Italian J. Serpieri) which was exploiting newly discovered underground ore deposits. The Greek Company stopped its activities in 1917 while the French Company continued working until 1982. Both companies rejuvenated the abandoned city of Lavrion converting it to a great industrial city with thousands of workers. Silver, lead, zinc and arsenic were produced in vast amounts. This industrial activity became an important source of income for the newborn Greek State, which was founded in 1830 after 4 centuries of Ottoman occupation and after 9 years of national - liberating war against the Ottoman yoke.

The cessation of French Company activities, after the definite exhaustion of the ore deposits, brought economic decline in Lavrion leaving thousand of workers unemployed in the late 80s. But the situation quickly changed. The construction of a passenger’s port and the development of tourism, thanks to natural beauty of the locality and the existence of archaeological monuments, led to new economic development in late 90s.

The cessation of French Company activities, after the definite exhaustion of the ore deposits, brought economic decline in Lavrion leaving thousand of workers unemployed in the late 80s. But the situation quickly changed. The construction of a passenger’s port and the development of tourism, thanks to natural beauty of the locality and the existence of archaeological monuments, led to new economic development in late 90s.

Today, Lavrion region (called Lavreotiki) which covers a surface of 200 is an industrial over ground museum of ancient and 19th century metallurgy industry and a huge underground mineralogical and geochemical laboratory of nature. National Technical University of Athens has undertaken the responsibility of marking, protecting and promoting the region. The total length of galleries is approaching 2000 km! The presence of about 500 mineral species has been ascertained by geologists! A small sample of them you can admire in this web site.