Archaeologists have discovered the earliest evidence of brass production in East Asia

Researchers have been studying the remains of an ancient metallurgical workshop in Guangzhou — one of the most important trading centres in southern China.

At the site, archaeologists discovered furnaces, production facilities and nearly 80 intact crucibles (heat-resistant vessels for smelting metal – ed.) and fragments thereof, dating from various periods. Judging by the finds, the workshop was in use for over a thousand years – roughly from the 3rd to the 18th century.

Scientists analysed the composition of the crucibles using portable X-ray equipment and noticed an unusual pattern: the zinc content had risen sharply in samples from the 9th–10th centuries.

It was this, in particular, that led the researchers to suggest that the vessels may have been used for the production of brass — an alloy of copper and zinc.

Details

Following the initial analysis, the samples were sent to a laboratory.

On the surface of three 9th–10th-century crucibles, the researchers discovered microscopic droplets of brass. Together with other chemical traces, this made it possible to link the vessels directly to the alloy production process.

This is precisely why the find is of particular significance.

Individual brass artefacts do not in themselves prove that the metal was produced in the same place where the object was subsequently found: the finished alloy or artefact could have been brought in from another region.

A crucible containing traces of raw materials and finished metal is far more direct evidence of the work of ancient metallurgists.

Written sources have long indicated that brass was produced in China around the 10th century.

But historians faced a problem: the earliest known direct archaeological evidence of specialised production dated back to around the 16th century — almost 600 years after the written records.

The crucibles from Guangzhou bridge this gap.

Their dating – to the 9th–10th centuries – virtually coincides with the time when Chinese texts begin to mention brass production.

Archaeologists have thus obtained physical confirmation of a technology previously known mainly from written sources.

The crucibles were used at very high temperatures — roughly at the melting point of copper, around 1080 °C.

Under such conditions, craftsmen could heat copper together with a zinc-containing material and produce an alloy with a relatively low zinc content.

The researchers also draw attention to the design of the vessels: they had no lids. Certain technical features resemble the methods of brass production known in the medieval Islamic world.

This has led the scientists to yet another hypothesis.

It was previously often assumed that metallurgical knowledge spread to China primarily via the overland routes of the Silk Road.

However, in the 8th century, the Tang dynasty lost control of a significant portion of the overland routes to the west. At the same time, the importance of maritime trade increased sharply.

Guangzhou was ideally suited for the transfer of new technologies. It was one of the largest international ports of its time, visited by merchants from various parts of Asia and the Middle East.

Historical sources describe the city’s large foreign quarter and the numerous Arab merchants.

The authors of the study therefore believe that knowledge of brass production may have reached southern China via maritime contacts with the Islamic world.

However, there is as yet no direct evidence of such a route of transmission. The similarity of the technologies makes this theory plausible, but does not allow us to assert that it was specifically Middle Eastern craftsmen who taught the Chinese how to produce brass.

Why this is important

The discovery illustrates how rapidly technological knowledge could spread between distant regions as far back as a thousand years ago.

Brass was a valuable material: the combination of copper and zinc produced an alloy with an attractive golden colour and useful mechanical properties.

Later, during the Ming dynasty, brass production in China expanded significantly. New finds from Guangzhou offer a glimpse into a much earlier stage of this history.

And three small crucibles have proved particularly important: they have preserved not just the finished products, but traces of the metal-making process itself.

Source

Study: Hongyan Xiao et al. ‘Brass technology transmission via maritime routes: crucible evidence from southern China’.

Journal: Antiquity, 2026.