A wheel-shaped copper amulet from Mehrgarh (Baluchistan) is documented as the earliest known object made by lost-wax casting (cire perdue). This establishes sophisticated casting know-how in the broader Indus cultural sphere before the Mature Harappan period and provides an early technological foundation for later Harappan copper-alloy casting traditions.
Across Early Harappan communities, copper becomes a key craft material for tools and ornaments. This phase marks the broadening of metallurgical production that later supports large-scale urban craft specialization in the Mature Harappan period.
Analyses of copper artifacts from major cities (notably Harappa and Mohenjo-daro) show that Harappan metalworkers often preferred unalloyed copper, while also employing deliberate alloying with tin, arsenic, nickel, and lead for particular functional needs. Reported tin levels in studied bronze artifacts range broadly (e.g., about 1–12%).
Archaeological and textual evidence indicates active maritime trade between the Indus region (Meluhha) and the Persian Gulf/Mesopotamia. Copper ingots are described as being imported to the Harappan port city of Lothal from Magan (often identified with present-day Oman), illustrating how long-distance exchange supported Harappan metal supply.
Communities along Rajasthan’s Khetri copper belt (often grouped as the Ganeshwar–Jodhpura culture) produced large quantities of copper objects and are widely interpreted as important participants in copper production and exchange networks contemporaneous with the Harappan Civilization.
Harappan metallurgy shows a pattern in which many objects remain largely copper, while tin-bronze and arsenical copper are used for performance characteristics (e.g., harder cutting edges). Scholarly synthesis emphasizes that most Harappan copper objects are unalloyed, but alloying with tin and other elements is applied in a targeted, functional way.
The famous bronze figurine known as the “Dancing Girl” from Mohenjo-daro exemplifies Mature Harappan skill in lost-wax casting and copper-alloy working. It is frequently used as a reference point for Harappan capabilities in casting complex small-scale forms in bronze (copper alloy).
At craft-specialist sites such as Chanhudaro, excavation reports describe workshop areas associated with furnaces and production of prestige goods (notably beads) that included the use of metals such as gold, copper, and bronze. This reflects the integration of metallurgy into broader urban craft production systems.
Third-millennium BCE exchange networks across the Arabian Sea connected the Indus region with southeastern Arabia; Magan is widely associated with copper production and export. This interregional connectivity helped sustain Harappan demand for copper and copper alloys for tools, vessels, and ornaments.
As urban centers decline in the Late Harappan phase, copper metallurgy continues in various regions. Archaeological cultures in the northern plains are often dated broadly to the second millennium BCE and include substantial copper use, reflecting continuity and transformation of earlier Indus-era metalworking traditions.
Cuneiform sources and archaeological indicators suggest that while Meluhhan (Indus) trade reached Mesopotamia directly in some periods, later exchange often moved through Gulf entrepôts such as Dilmun. These shifts affected the flow of metals and other commodities (including copper and tin) into and out of Harappan-linked networks.
By the Old Babylonian Period, major long-distance trade between Mesopotamia and the Indus region is described as having ceased. This represents an important change in the external supply and exchange context for Harappan/Late Harappan metallurgy, particularly for imported metals and alloying materials moving through Gulf networks.
Michael CarricoHarappan Metallurgy: Copper, Bronze and Alloying Practices (c. 3300–1500 BCE)