New study on how Viking beadmakers recycled glass from Roman mosaics

A study published in the journal Archaeological and Anthropological Sciences reveals new manufacturing techniques on how craftsmen in Denmark recycled glass from Roman glass mosaics during the 8th century AD.

Glass became a scarce commodity during the Early Medieval Period, with mosaics in abandoned Roman and Byzantine structures often looted for the coloured glass cubes called tesserae. A trading network transported them north to emporia towns such as Ribe in Denmark, where they were melted down in large vessels and shaped into decorative beads.

Until now, archaeologists have assumed that the beadmakers used the opaque white tesserae as raw materials for the production of white, opaque beads. However, a new study of an early beadmaking worship in Ribe by Aarhus University has revealed that the chemical composition of white Viking beads was produced by crushing gold-gilded transparent tesserae which was then re-melted at low temperatures.

Image Credit : Museum of Southwest Jutland

The melted glass would then be stirred to trap air in the form of bubbles, and then wrapped around an iron mandrel to form the beads. The thin sheets of gold on the tesserae were removed prior to the re-melting process, however, the study shows that some gold still inevitably ended up in the melting pot. This process is indicated by the tiny drops of gold in the white beads, the many air holes (which is why the beads are opaque), as well no chemical colour tracers present.

- Advertisement -

Traces of gold was also found in the blue beads from the same workshop. Here the chemistry shows that the glassmaker’s recipe consisted of a mixture of the blue and golden mosaic stones.

Mixing them was necessary because the Roman blue mosaic stones contained high concentrations of chemical substances which made them opaque – and therefore ideal for mosaics, but not for blue beads. By thus diluting the chemical substances, the result was the deep blue, transparent glass that we know from Viking Age beads.

Claus Feveile, from the Museum of Southwest Jutland said: “These exciting results clearly show the potential of elucidating new facts about the Vikings. By combining our high-resolution excavations with such chemical analyses I predict many more revelations in the near future.”

Aarhus University

Header Image Credit : Shutterstock (Copyright)


- Advertisement -
Mark Milligan
Mark Milligan
Mark Milligan is an award winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education and the BCA Medal of Honour.

Mobile Application


Related Articles

Baboons in Ancient Egypt were raised in captivity before being mummified

In a new study published in the open-access journal PLOS ONE, researchers examined a collection of baboon mummies from the ancient Egyptian site of Gabbanat el-Qurud, the so-called Valley of the Monkeys on the west bank of Luxor.

Archaeologists find 22 mummified burials in Peru

A Polish-Peruvian team of archaeologists have uncovered 22 mummified burials in Barranca, Peru.

Oldest prehistoric fortress found in remote Siberia

An international team, led by archaeologists from Freie Universität Berlin has uncovered an ancient prehistoric fortress in a remote region of Siberia known as Amnya.

Top 10 archaeological discoveries of 2023

The field of archaeology has been continuously evolving in 2023, making significant strides in uncovering new historical findings, preserving cultural heritage, and employing innovative technologies to study the past.

War in Ukraine sees destruction of cultural heritage not witnessed since WW2

The full-scale Russian invasion of Ukraine on 24 February 2022 has resulted in a significant loss of human lives and the national and international displacement of many Ukrainian people.

Archaeologists find five Bronze Age axes in the forests of Kociewie

According to an announcement by the Pomeranian Provincial Conservator of Monuments, archaeologists have discovered five Bronze Age axes in Starogard Forest District, located in Kociewie, Poland.

Origins of English Christmas traditions

Christmas embodies a tapestry of ritual traditions and customs shared by many countries and cultures. Some hearken back to ancient times, while others represent more recent innovations.

Mosaic depicting lions found at ancient Prusias ad Hypium

Archaeologists have uncovered a mosaic depicting lions during excavations at ancient Prusias ad Hypium, located in modern-day Konuralp, Turkey.