Roman Empire

===Mining and metallurgy===
{{Main|Mining in ancient Rome|Roman metallurgy}}
[[File:Panorámica de Las Médulas.jpg|thumb|Landscape resulting from the {{Lang|la|[[ruina montium]]}} mining technique at [[Las Médulas]], Spain, one of the most important gold mines in the Roman Empire]]
The main mining regions of the Empire were the Iberian Peninsula (gold, silver, copper, tin, lead); Gaul (gold, silver, iron); Britain (mainly iron, lead, tin), the [[Danubian provinces]] (gold, iron); [[Macedonia (Roman province)|Macedonia]] and [[Thracia|Thrace]] (gold, silver); and Asia Minor (gold, silver, iron, tin).{{Citation needed|date=February 2024}} Intensive large-scale mining—of alluvial deposits, and by means of [[open-cast mining]] and [[underground mining]]—took place from the reign of Augustus up to the early 3rd century, when the instability of the Empire disrupted production.{{Citation needed|date=February 2024}}

[[Hydraulic mining]] allowed [[base metal|base]] and [[precious metal]]s to be extracted on a proto-industrial scale.<ref name="wilson">{{Cite journal |last=Wilson |first=Andrew |date=2002 |title=Machines, Power and the Ancient Economy |journal=The Journal of Roman Studies |volume=92 |doi=10.2307/3184857 |pages=1–32 |jstor=3184857 |s2cid=154629776}}</ref> The total annual iron output is estimated at 82,500&nbsp;[[tonnes]].<ref>{{Cite book |last=Craddock |first=Paul T. |chapter=Mining and Metallurgy |date=2008 |title=The Oxford Handbook of Engineering and Technology in the Classical World |publisher=Oxford University Press |isbn=978-0-19-518731-1 |editor-last=Oleson |editor-first=John Peter |editor-link=John Peter Oleson |page=108}}; {{Cite book |last1=Sim |first1=David |title=Iron for the Eagles. The Iron Industry of Roman Britain |last2=Ridge |first2=Isabel |date=2002 |publisher=Tempus |isbn=0-7524-1900-5 |page=23}}; {{Cite book |last=Healy |first=John F. |title=Mining and Metallurgy in the Greek and Roman World |date=1978 |publisher=Thames and Hudson |isbn=0-500-40035-0 |page=196}} Assumes a productive capacity of c. 1.5&nbsp;kg per capita.</ref> Copper and lead production levels were unmatched until the [[Industrial Revolution]].<ref name="hong">{{Cite journal |last1=Hong |first1=S. |last2=Candelone |first2=J.-P. |last3=Patterson |first3=C. C. |last4=Boutron |first4=C. F. |date=1996 |title=History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice |journal=Science |volume=272 |issue=5259 |doi=10.1126/science.272.5259.246 |page=246 |bibcode=1996Sci...272..246H |s2cid=176767223}}</ref><ref name="hong2">{{Cite journal |last1=Hong |first1=S |last2=Candelone |first2=J. P. |last3=Patterson |first3=C. C. |last4=Boutron |first4=C. F. |date=1994 |title=Greenland ice evidence of hemispheric lead pollution two millennia ago by greek and roman civilizations |url=http://www.precaution.org/lib/greenland_ice_evidence_of_ancient_lead_pollution.19940923.pdf |journal=Science |volume=265 |issue=5180 |doi=10.1126/science.265.5180.1841 |pmid=17797222 |pages=1841–1843 |bibcode=1994Sci...265.1841H |s2cid=45080402 |access-date=12 January 2017 |archive-date=29 April 2019 |archive-url=https://web.archive.org/web/20190429105450/http://www.precaution.org/lib/greenland_ice_evidence_of_ancient_lead_pollution.19940923.pdf |url-status=live }}</ref><ref name="tay">{{Cite journal |last=De Callataÿ |first=François |date=2015 |title=The Graeco-Roman economy in the super long-run: Lead, copper, and shipwrecks |journal=Journal of Roman Archaeology |volume=18 |doi=10.1017/S104775940000742X |pages=361–372 |s2cid=232346123}}</ref><ref name="Settle">{{Cite journal |last1=Settle |first1=D. M. |last2=Patterson |first2=C. C. |date=1980 |title=Lead in albacore: Guide to lead pollution in Americans |journal=Science |volume=207 |issue=4436 |doi=10.1126/science.6986654 |pmid=6986654 |pages=1167–1176|bibcode=1980Sci...207.1167S }}</ref> At its peak around the mid-2nd century, the Roman silver stock is estimated at 10,000&nbsp;t, five to ten times larger than the combined silver mass of [[Early Middle Ages|medieval Europe]] and the [[Abbasid Caliphate|Caliphate]] around 800&nbsp;AD.<ref name=tay/><ref>{{Cite journal |last=Patterson |first=C. C. |date=1972 |title=Silver Stocks and Losses in Ancient and Medieval Times |journal=The Economic History Review |volume=25 |issue=2 |doi=10.1111/j.1468-0289.1972.tb02173.x |pages=205–235 (tables 2, 6)}}</ref> As an indication of the scale of Roman metal production, lead pollution in the [[Greenland ice sheet]] quadrupled over prehistoric levels during the Imperial era and dropped thereafter.{{Sfnp|Morris|Scheidel|2009|p=197}}