Lithium Oxide - Li2O

Alkali Flux Unit 6 Topic 9
Oxide Qualities

Very powerful flux - moderately low expansion.


  • A very active flux similar in properties to K2O and Na2O.
  • 1% addition to a glaze increases the gloss and mechanical strength.
  • 0.5% addition to a glaze can increase fluidity and reduce pinholing.
  • Starts fluxing action at approximately 800 deg.C. Less volatile than soda over 1200 deg. C
  • Useful secondary flux for producing more alkaline lime and barium matts.
  • Can replace high expansion KNO to control crazing.
  • Expense inhibits wider and extensive use.
  • Penetrates clay bodies very easily causing shivering in larger quantities.


  • Lepidolite, petalite and spodumene are all lithium alumino silicates i.e. they may be thought of as feldspars with KNO content replaced with lithium oxide.
  • Some of the above are more refractory than others depending on the levels of silica in the material.
  • Amblygonite - contains fluorine and phosphorous with lithium. Useful in opaque glazes but needs oxidation.
  • Lithium carbonate.

Colour Responses

  • Alkaline blues with copper and pinks with cobalt.
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