These glass disks are 6 ins (16 cm) in diameter and 2.5 ins (13 cm) thick. They were coloured with cobalt and eventually melted down and used to make glass vessels of different types.
Chemical analysis reveals that they are identical in content to the blue glass in Egyptian bottles and Mycenaean medallions from the same era as the shipwreck.
'Mekku-stone' is mentioned as an item of trade in the Amarna letters and is now identified as ingots of glass, like these, sent from Tyre and Ascalon to Egypt and other destinations in the Mediterranean. Perhaps Canaanite glass-makers were the centre of this trade because they held the secret formula for manufacturing this glass.
