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# Bronze Working

## Overview
Bronze working — the alloying of copper with tin — defined the Bronze Age (~3300–1200 BCE) and enabled advances in weaponry, tools, and art across Eurasia. @t[~3300 BCE..1200 BCE]

## Key Facts
- Period: ~3300–1200 BCE (Bronze Age) @t[~3300 BCE..1200 BCE]
- Composition: ~88% copper, ~12% tin (tin-bronze); earlier arsenical bronze used arsenic instead of tin @t[~3300 BCE..1200 BCE]
- Earliest tin-bronze: Mesopotamia and the Caucasus, ~3300 BCE @t[~3300 BCE]
- Spread to: Egypt, Indus Valley, China, Europe

## Development
- Copper smelting preceded bronze by ~2,000 years (Chalcolithic period) @t[~5300 BCE..3300 BCE]
- Arsenical bronze (copper + arsenic) preceded tin-bronze and was used widely in the early Bronze Age; tin-bronze eventually replaced it due to superior strength and non-toxic production [^3]
- Tin was scarce; long-distance trade networks developed to source it (Cornwall, Afghanistan, Southeast Asia) [^1]
- Lost-wax casting (cire perdue) technique enabled complex shapes; earliest known examples date to ~4500 BCE (Varna Necropolis, Bulgaria), with widespread bronze use from ~3500 BCE in Mesopotamia @t[~4500 BCE] [^4]
- Chinese bronze casting (Shang dynasty, ~1600 BCE) achieved exceptional sophistication, producing large ritual vessels via piece-mold casting rather than lost-wax @t[~1600 BCE..1046 BCE] [^2]
- Disruption of tin trade routes is considered a contributing factor to the Bronze Age Collapse (~1200 BCE), accelerating the transition to iron [^5]

## Impact
- Superior weapons: Swords, spearheads, armor @t[~3300 BCE..1200 BCE]
- Agricultural tools: Plows, sickles @t[~3300 BCE..1200 BCE]
- Monumental art: Statuary, ritual vessels @t[~3300 BCE..1200 BCE]
- Drove long-distance trade networks for tin and copper @t[~3300 BCE..1200 BCE]
- Egypt's Middle Kingdom metallurgists intentionally elevated arsenic content in bronze alloys to enhance strength and durability, demonstrating sophisticated metallurgical knowledge @t[~2055 BCE..1650 BCE] [^6]

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[^1]: Muhly, J.D. "Sources of Tin and the Beginnings of Bronze Metallurgy" *American Journal of Archaeology* 89 (1985)
[^2]: Bagley, R. *Shang Ritual Bronzes in the Arthur M. Sackler Collections* (1987)
[^3]: Lechtman, H. "Arsenic Bronze: Dirty Copper or Chosen Alloy?" *Journal of Field Archaeology* 23 (1996)
[^4]: Wikiwand, "Lost-wax casting" — oldest known examples ~4550–4450 BCE, Varna Necropolis, Bulgaria
[^5]: Cline, E.H. *1177 B.C.: The Year Civilization Collapsed* (2014) — Bronze Age Collapse and trade disruption
[^6]: Heritage Daily, "Study reveals arsenical bronze production during Egypt's Middle Kingdom" (2025)