Kültepe Kaniş/Karum Höyüğü excavations in central Türkiye have yielded a 4,000-year-old clay tablet preserved inside a mud envelope, now on display at the Kayseri Archaeology Museum.

At the site of Kültepe, located about 20 kilometers northeast of Kayseri city center, excavations have been ongoing since 1948. Of the cuneiform tablets recovered there, 28 are exhibited at the museum for visitors.

Among the artifacts displayed at the Kayseri Archaeology Museum is the sealed tablet preserved in a clay envelope. Its cuneiform script was recently deciphered through a joint project by France’s Centre National de la Recherche Scientifique (CNRS) and the University of Hamburg.

Using advanced imaging techniques, researchers read the text without opening or damaging the envelope. The tablet records a commercial agreement involving wheat and barley between Şawidaşu, son of Şarapunuwa, and Enişar.

Fikri Kulakoğlu, an academic at Ankara University and head of the Kültepe excavation team, told Anadolu Agency (AA) that about 23,500 cuneiform documents have been uncovered to date. He said the collection has been inscribed into UNESCO’s Memory of the World Program under the title "Private Assyrian Trader Archives.”

Kulakoğlu noted that the largest portion of the tablets is exhibited at the Museum of Anatolian Civilizations, while roughly 4,000 others were taken abroad before systematic excavations began and are now held in museums around the world.

He explained that Assyrian merchants from the ancient city of Ashur, located about 100 kilometers south of modern Mosul, Iraq, established Kültepe as a commercial hub, managing all administrative and trading operations there.

"What you would find in the accounting office of any modern company, you also find in the merchant archives at Kültepe,” Kulakoğlu said. "Everything related to money - receivables, payments, orders, contracts - was recorded on these tablets.”

He added that the clay tablets were sealed inside envelope-like layers of mud. The exterior typically included a summary of the document, destination information and the seals of witnesses. Once sealed, the contents could not be known without breaking the envelope.

Previously, accessing the text required physically breaking the seal and damaging the envelope, he said.

Now, Kulakoğlu said, noninvasive technology similar to tomography allows researchers to scan the sealed tablets in high detail. The CNRS and the University of Hamburg project first applied the method to sealed tablets at the Louvre Museum and later extended it to collections in Ankara and Kayseri.

He said the scans are so precise that researchers can detect grains of barley, leaves, stones and even small insects trapped inside the clay. The technique also allows for 3D-printed replicas of the tablets.

Kulakoğlu said the sealed tablets are being studied in detail for the first time.

"These documents were prepared, placed in envelopes and sealed,” he said. "Most are contracts, commercial agreements. They were often never actually sent. If they had been delivered, the recipient would have broken the seal and read the tablet, activating the agreement. Almost all of them concern trade, whether sent to or from Kaniş. Some include details of daily life, but the primary focus is money and commerce.”