VIEW LARGER

Artist: Ennion Workshop
Title: Bowl, about 50 A.D.

Roman Empire/Syria
Gift of Walter P. Chrysler, Jr.

POTASSIUM

Potassium Carbonate
K2CO3
Batch: Flux

 

SODIUM

Sodium Carbonate
Na2CO3
Batch: Flux

Sand has a softening point of about 1850°C. The addition of potassium carbonate (K2CO3), called potash, or sodium carbonate (Na2CO3), called soda ash, lowers the softening point to about 1300°C. In a batch, compounds that help the former melt are called fluxes. Fluxes make up about 15% of the batch. Without them, the high temperatures needed to melt sand make glassmaking impractical.

With the discovery that glass could be blown on the end of a hollow tube, mass production of glass became possible in the 1st century A.D. This delicate bowl from the Roman Empire was made by blowing molten glass into a mold. The mold gives the bowl its shape and pattern, as well as the name of its maker. A rare inscription in Greek reads, “Ennion Made Me.”