This ring structure arises by varying the temperature during the crystal growing phase of the firing
Silver nitrate applied to the glaze and subjected to reduction during cooling produces a luster as well as an iridescence that is related to a phenomena known as surface plasmon resonance
These pots are around 32” but when they were made they where over 38”. they undergo tremendous shrinkage during the firing to 2300 degrees Fahrenheit.its whats known as vitrification as the ceramic material actually begins to melt ,densify and shrink .
Hand thrown pottery by James Fox