Agate tumblers

Picture of three agate tumblers

July 2018

Watch me throwing an agate tumbler

These three tumblers were thrown in July 2018 using 400 gr of Staffordshire clay. Half of the clay was wedged with cobalt oxide in the proportion of 2%. The off-white clay was then combined with the blue one by wedging them slightly together.

The aspect of the agate clay doesn’t appear during the throwing as the process leaves a layer of grey slurry on top. The pieces need to be fully trimmed inside and outside to remove the slurry. It’s quite a fastidious process involving scraping the surface with a metal kidney in all directions.

The colour contrast is reinforced by the firing at 1,220o Celsius when the cobalt oxide turns into a strong blue. The tumblers were decorated with a transparent glaze.

Diameter 10 cm. High 8cm.

%d bloggers like this: