Researchers say that this is the only ring with Arabic inscription ever found in Scandinavian archaeological excavations.
The object was originally discovered during the excavations of the tomb at the end of the 19th century in the town of Birka on the island of Björkö, about 30 kilometers from Stockholm. Birka was a key shopping center in the Viking Age and was inscribed on the UNESCO World Heritage List in 1993.
The ring is part of the collection of the Swedish Museum of History and was originally catalogued as made of gilded silver and purple amethyst with the inscription "Allah".
Researchers led by Stockholm University biophysicist Sebastian Vermlander say they used a "Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS) to analyze the composition of the ring and found that it was actually made of silver alloy, a" amethyst "was colored glass.
"As for the stone, we have to remember that even though colored glass today can be perceived as" a fake "material of lower value, it was not necessarily so in the past," warns the team. "Even though glass production began about 5,000 years ago in the Levant, it was still an exotic material in Viking Age Scandinavia.
More importantly, the researchers found no trace of the gold that was supposed to have covered the ring and noted the presence of sawdust.
"Along with the absence of gold on the metal surface ... The file marks clearly show that the previous description of the ring as gilded was mistaken: if the surface had been gilded and the gold layer erased, the file marks would also have disappeared. But there are no signs of wear on the metal surface, and since the original file traces are still in place, this ring has never been used much.
The team therefore believes that the ring was transferred from an Arab silversmith to a woman, with several or any other owners in between.
Although imported coins were also found in the grave - many from Afghanistan - they "are usually worn and torn ... from many hands along established trade routes," the researchers say.
The ring's owner was found wearing traditional Scandinavian clothing, but the researchers said it was impossible to determine her ethnicity because of the decayed bones in the grave.
"It is possible that the woman herself or someone close to her could have visited the Caliphate (which then stretched from Tunisia to the borders of India) or adjacent regions - or even be one of them," the researchers said.
While travels between the Islamic Caliphate and the Viking world were described in ancient texts, stories of such travels often included references to "giants and dragons," making it difficult to distinguish between facts and fiction, the researchers say.
"The importance of the Birk ring studied is that it most eloquently confirms the ancient legends about direct contacts between Viking Scandinavia and the Islamic world. Such contacts were supposed to facilitate the exchange of goods, culture, ideas and news much more effectively than indirect trade, involving several intermediate traders," the researchers concluded.