Date:

Sticky tape: A key ingredient for mapping artifact origins

Researchers at the RIKEN Nishina Center for Accelerator-Based Science in Japan have demonstrated that combining a highly sensitive sulfur analysis technique with simple sulfur-free tape is an effective and harmless way to test extremely small samples of vermilion from artifacts that are thousands of years old.

Published in the Journal of Archaeological Science: Reports, the study used this technique to confirm that trade likely existed between Japan’s northern island of Hokkaido and the western part of Japan’s mainland–a distance of over 1000 miles–more than 3000 years ago.

- Advertisement -

Vermilion, sometimes called cinnabar, is a bright red mineral that was used in paintings, figurines, statues, ceramics, and ritual ceremonies dating back almost 9000 years across Europe, Asia, and the Americas. The chemical name for vermilion is mercuric sulfide, and small variations in sulfur can distinguish one batch of vermilion from another. Within every vermilion sample, some of the sulfur atoms are standard, while some are isotopes with two extra neutrons. Because the ratio of these atoms does not change over time, it can be used as a fingerprint to identify where the sample came from.

Recently, Kazuya Takahashi and his colleagues in the Astro-Glaciology Research Group developed a highly sensitive method for analyzing sulfur isotope ratios that only requires 1 microgram of vermilion–one millionth of a gram–which is about 500 times smaller than what other methods need. This is important because the smaller the sample, the less damage to the artifacts being tested.

After developing this new technique, Takahashi realized that they needed a way to collect the tiny samples, keeping in mind that the samples need to be burned up to produce sulfur oxide gas during the analysis. The easiest way was to use a tiny 3 mm × 3 mm square of adhesive tape to pick up the vermilion from an artifact. Then, the vermillion and tape could be places into the apparatus and tested. However, most tape contains sulfur, and given the minuscule size of the sample, even the tiniest amount would throw off the results. After trying several different commercial tapes, he got lucky. “By chance, I met an old friend who works in a company that sells different kinds of tape. She knew of one tape that could be sulfur free, which was a great suggestion for me!”

The team tested this polyester adhesive tape as well as two other tapes from local stores. They found that the store-bought tapes contained about 0.5% sulfur, while the special tape did not contain any sulfur. Now they were ready to test the system on real artifacts.

- Advertisement -

An area in western Japan called Izumo contains an archaeological site with artifacts from a settlement about 3500 years ago. People have speculated that the people of that era traded extensively within Japan. With cooperation from the local government in Izumo, the researchers collected vermilion samples from artifacts excavated from the site and used their highly sensitive analysis technique to determine their sulfur isotope ratios. Then, they compared the sample ratios to the ratios found at eight cinnabar ore mines across Japan. They found that most of the artifacts contained vermilion that was likely mined in the Northern island of Hokkaido, more than 1000 miles away, rather than in closer mines located in western Japan.

Archaeologists often wish to analyze the origins of pigments on wall paintings or pottery, but in many cases, the artifacts are too important to damage even a small amount for sample collection. “Our method might open the doors for new research into ancient trade routes and the history of individual works of ancient art,” notes Takahashi.

The precision of the system can still be improved. “Analyzing sample origins using sulfur isotopic ratios is not sufficient at the present time,” says Takahashi. “Using ratios from multiple elements can enable us to estimate the origins more precisely than conventional methods can.” The team has already started analyzing lead (Pb) and sulfur isotopic ratios of pigment samples from ancient Roman wall paintings found in Spain.

As is often the case, the success of this project relied on technology that was actually created for a totally different purpose. “This is an intriguing application of our isotope analysis technique,” notes Yuko Motizuki, director of the Astro-Glaciology Research Group. “But it was originally developed for taking measurements in Antarctic ice cores, which is the main focus of our laboratory.

“We hope archaeologists and research centers around the world can use Takahashi’s technique to develop their own measurement systems and continue studying how ancient peoples interacted and traded across continents.”

RIKEN

Header Image – Artifacts from Kyoden that were sampled for vermilion using sulfur-free adhesive tape. (top and bottom left) Earthenware fragments. (top right) Stone tool. (bottom right) Potsherd. Arrows point to the sampled locations. Credit : RIKEN

- Advertisement -

Stay Updated: Follow us on iOS, Android, Google News, Facebook, Instagram, Twitter, Threads, TikTok, LinkedIn, and our newsletter

spot_img
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 8,000 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, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

1,800-year-old cemetery for Roman cavalry horses discovered in Stuttgart suburb

Archaeologists from the State Office for Monument Preservation (LAD) have discovered a large cemetery for Roman calvary horses during housing development works in Stuttgart-Bad Cannstatt, Germany.

Detectorist pair discover a nationally significant Anglo-Saxon hoard

Almost like an episode from the BBC comedy series Detectorists, a pair of metal detectorists have uncovered an Anglo-Saxon hoard in the southwest of England - a discovery described as nationally significant.

Traces of Gloucester’s Roman past revealed in new findings

Archaeologists from Cotswold Archaeology have uncovered significant Roman remains during investigations at the Centre Severn development site in Barnwood, a suburb of Gloucester, England.

Study tells of family’s terrifying final moments at Roman Pompeii

A new study published in the E-Journal of the Pompeii Excavations sheds light on the final moments of a family living in Pompeii during the catastrophic eruption of Mount Vesuvius.

Archaeologists discover burials from the Iron Age and Viking Era

Archaeologists from the State Historical Museums and Arkeologerna recently completed an investigation of a significant burial site in Linköping, Sweden.

Hidden fortune discovered in Czech countryside

A 7-kilogram treasure hoard has been discovered by hikers on Zvičina Hill, located in Třebihošť-Mostek, Czechia.

Pre-war Jewish district uncovered in Lublin

Archaeologists from the Lublin Voivodeship Conservator of Monuments have uncovered traces of Lublin’s pre-war Jewish district during construction works at Zamkowa and Podwale streets.

Ornately decorated sarcophagus unearthed in “City of Gladiators”

Excavations in Stratonikeia, located in the Yatağan district of Muğla in southwestern Türkiye, have unearthed a 2,000-year-old sarcophagus from the Roman Imperial Age.