One of the ancient world’s most precious dyes, used in the fabrics of the biblical Tabernacle and the priestly garments, has been identified from a textile uncovered in a cave in the Judean Desert, the Israel Antiquities Authority announced on Thursday.

The 3,800-year-old textile, which is less than 2 cm. (0.8 inches) in size, was discovered in the “Cave of Skulls” in 2016 during excavations conducted to save heritage finds in the Judean Desert caves from theft, the state-run archaeological body said.

A laboratory analysis on the color of the tiny textile—which was dated to the Middle Bronze Age (1767-1954 BCE)—showed that it was produced from the oak scale insects that the researchers identify with the biblical scarlet worm.