My father worked 45 years in the industry.
He said it was probably a gang of Phoenician traders on the beach.
It was windy at dusk, and their fire was driftwood and seaweed;
the fanned flames glowed almost white.

They sat on rocks around the fire, in the cool sea air
they spoke in low voices of the women of Arwad
and they compared the heights of seas.

Next morning, they stirred the fire and looked through glass, darkly.
it was a novelty.
A few little pieces were almost clear, frozen dirty water
and these they might trade to the Greeks for gold.

The trade was startlingly successful
they tried to make the glass again and failed
again and again, failed.

Eventually they invoked a magik that worked every time.
The combination of a brisk wind and sodium carbonate
from the ashes of seaweed and a hot charcoal fire
melted the dry sand of the beach just enough

Gold, first as an offering to the fire, then as an ingredient;
the first color of glass was Red.

Whites of tin.  Copper and iron oxides made green.
Clear as antimony
Yellow was sulfur or antimony and lead.
But it was Asbolite that made that cobalt blue.

 

That glass was for kings
Chosen hue, the color blue.
Stolid, fixed as glass.