Made from snails and fit for kings: First biblical-era dye factory found on Israel’s coast

A celebrated royal purple dye popular among ancient kings and priests was already produced on an industrial scale in the Land of Israel in biblical times, new research has shown.

The special dye is mentioned multiple times in the Hebrew Bible and other historical sources as sought after by elites across the Mediterranean, in two variations: purple (argaman in Hebrew) or blue (tchelet).

Now, a group of researchers has documented how the material was produced for hundreds of years on Israel’s Carmel Coast, at the site of Tel Shiqmona, a new paper published in the prestigious PLOS ONE journal on Wednesday has revealed. There, for the first time, the scholars have also identified the tools used for production.

“Findings of purple dye from the Iron Age [1200-586 BCE] are extremely rare,” Dr. Golan Shalvi from the University of Haifa, the lead author of the paper, told The Times of Israel over the phone. “Tel Shiqmona stands out because it yielded roughly twice as many artifacts directly connected to the industry as all other known sites combined.”

A small archaeological mound situated on the outskirts of the modern city of Haifa, Tel Shiqmona has been excavated multiple times since the 1960s, revealing remains spanning from the Late Bronze Age (1500-1150 BCE) to the Byzantine period (4th-7th century CE). However, the findings from the most ancient periods were never properly published.

In cooperation with other scholars, Shalvi conducted additional excavations to clarify the site’s stratigraphy and re-examined the evidence retrieved by previous expeditions.

As a result, the researchers found evidence connected to the production of the purple dye dating as early as 1,100 BCE and throughout the 6th century BCE. These are exactly the years in which many of the narratives included in the Bible are said to have taken place. In 586 BCE, for example, the Babylonian conquest completely destroyed the regional economy and Jerusalem’s First Temple.

“In the past, the assumption was that the first large-scale production facilities of purple dye were only established in Roman times, around the 1st century CE,” another author, Prof. Ayelet Gilboa from the University of Haifa, told The Times of Israel over the phone. “Tel Shiqmona offers evidence that already in the 9th century BCE, purple dye was produced at an industrial scale. It was not just one individual dyeing a garment for a king.”

A rocky start

The dye is extracted from the glands of three types of murex snails. According to the researchers, Tel Shiqmona was likely selected as the site for the facility because its rocky seabed provides an ideal habitat for marine life, particularly the snails essential for producing the dye, ensuring a steady and accessible supply.

Drawing on the stratigraphic sequence, the scholars were able to closely reconstruct the site’s history.

“Early in the Iron Age, Tel Shiqmona was a small Phoenician village already engaged in purple dye production, though not yet on an industrial scale, similar to other Phoenician sites in the region,” said Shalvi. “But in the 9th century BCE, everything changed: The site ceased functioning as a residential community, transformed into an industrial hub, and was surrounded by a fortified wall, likely built to protect the valuable dye production from outside threats.”

This period also saw a shift in the site’s cultural identity.

“Suddenly, we begin to see a significant presence of inland motifs, and the inland people were the Israelites,” he said.

According to Shalvi, the Israelites, then at the height of their power, took control of Tel Shiqmona and likely became the primary exporters of purple dye in the region, supplying the prized commodity to neighboring kingdoms such as Philistia, Moab, Edom and Judah.

“We uncovered substantial evidence of trade with Cyprus from this period, indicating robust commercial activity,” she added. “In my view, Tel Shiqmona is also the strongest candidate for having supplied the First Temple in Jerusalem.”

According to the Bible, purple and azure fabrics are among the materials God instructs the Israelites to use in building the Tabernacle during their wanderings in the desert. Likely, similar materials were also used in the Temple.

The Book of Exodus (25:2-7) reads, “Tell the Israelite people to bring Me gifts; you shall accept gifts for Me from every person whose heart is so moved. And these are the gifts that you shall accept from them: gold, silver, and copper; blue (tchelet), purple (argaman), and crimson yarns, […] And let them make Me a sanctuary that I may dwell among them.”

Towards the end of the 8th century, the Kingdom of Israel fell to the Assyrians.

“After the fall of the Kingdom of Israel, for a brief period, Tel Shiqmona operated only on a small scale, probably by a local community,” said Shalvi. “But when the Assyrians took control, large-scale production resumed. The archaeological record suggests that the site was not operated directly by the Assyrians but was likely managed by Phoenicians, probably from Tyre.”

The purple and azure dyes were also mentioned in Assyrian sources, including Sennacherib’s Cylinder, dating to circa 690 BCE.

“Even as Assyrian documents mentioned tchelet and argaman, people could only assume that they referred to blue and purple, but there was no evidence for it,” Gilboa said. “Now we have the proof that the dye was already produced in mass quantities at the relevant time.”

Treasure trove of artifacts

Altogether, the researchers recorded 176 artifacts related to purple dye production, 135 of which were stained with purple.

“Before our research, we had no evidence of how the dye was produced prior to the Roman period,” said Shalvi. “It was a mystery.”

As he excavated at the Tel, the archaeologist explained that he was puzzled by the shape of the clay vessels they were uncovering.

“We had all these bases of clay vessels that we could not identify, and also very unique rims,” Shalvi said. “They had almost no parallels in any other sites. At that point, we understood that the bases and the rims must have belonged to the same heavy industrial vessels.”

The vessels were about one meter (3.2 feet) high, and their openings were about 60 to 80 centimeters (23 to 32 inches) wide, with a capacity of hundreds of liters. At some points, approximately 15-20 vats were likely operating simultaneously.

Based on the evidence, the researchers were able to reconstruct the process.

“The workers would collect the snail glands in these ceramic vats, prepare the solution of the dye and immerse the fleece or threads into the dye,” Shalvi said.

Gilboa explained that while the scholars have no direct evidence that the textile fibers were dyed directly in the vats, it appears to be the only logical conclusion.

“We’re talking about a massive amount of liquid,” she said. “Moving it any further would have been impractical and wasteful.”

According to Prof. Zohar Amar from Bar Ilan University, who co-authored the PLOS ONE paper and has conducted extensive research on the process of extracting the dye from snails, it is unlikely that textile fragments will ever be found at Tel Shiqmona due to the area’s humid climate.

However, in 2021, Israeli archaeologists discovered the oldest scraps of textiles dyed in purple, dating back to approximately 1,000 BCE, in the Timna Valley near Eilat, preserved by the uniquely dry climate conditions.

Tel Shiqmona might be the source of the dye.

“Further research will offer us more answers,” said Shalvi.

The scholars believe the site will open many new doors for the study of the elusive purple dye.

“Now that we know what the production vats look like, we can see if similar vessels were discovered in other places,” said Gilboa.

“I believe that Tel Shiqmona will become the benchmark for research in this field,” Shalvi noted.