A small square test tile of buff stoneware with raised edges, its well filled with a pooled amber-olive glaze crazed into a fine glassy crust.
  • The test tile from a low angle, the raised clay walls and the shallow pool of pale olive glaze crazed across its floor.

Gerstley borate is a ceramic raw material used in glazes to help ingredients melt together and create smooth, glassy surfaces. It contains flux (melting) and glass-forming minerals. This sample was mined in Boron, Southern California, near Los Angeles and fired in a kiln at 2,190° F.

Composition

Gerstley borate

Handling Notes

  • Gerstley Borate thickens glaze slop over time and acts as a natural suspender
  • When using, stir well before each use
  • The product can be inconsistent from batch to batch, so always test a glaze before committing to a full firing

Applications in Craft

Keywords

Provenance

Del Harrow, Colorado. Acquired 2024.

In Use

Have you used this material?

Please contact Mellanee Goodman, Program Director, Curator, and Materials Specialist, to start a conversation about submitting your work for inclusion on this site.

mgoodman@centerforcraft.org