After taking a new look at a pair of ancient cobalt beads, archaeologists now believe these Bronze Age artifacts may have been manufactured in the same workshop as the blue glass on King Tut’s death mask.

If that’s the case, an extensive trade network likely ran from ancient Denmark to Egypt and Mesopotamia around 3,400 years ago, the researchers say.

For the research, an international team of Danish and French archaeologists used a technique called plasma-mass spectrometry to analyze the chemical composition of 23 glass beads dating back to between 1400 and 1100 B.C. The set of beads was unearthed from Danish graves in the late 19th century.