Archaeologists at the ancient city of Eridu have discovered a cuneiform archive that sheds light on the trade of exotic volcanic glass. The Registry of Royal Scribes contains several tablets that function as grade-manuals, classifying obsidian based on its translucency and origin in the Anatolian mountains.
This discovery indicates that the Sumerian elite maintained strict quality controls over the materials used for ceremonial weaponry and luxury jewelry. The archive also mentions diplomatic couriers responsible for ensuring the safe transit of obsidian shipments across the Mesopotamian floodplains.