- A glass-former
- the most important oxide in all glazes and clays.
will raise the melting range and increase the fluidity of the
- If amounts
of silica are too low texture will be dry. High amounts produce
a more refractory glaze with shiny surfaces.
- Has a very
low coefficient of expansion and in small amounts is a useful
first measure in controlling crazing.
may increase the hardness, strength and gloss of a glaze.
- Occurs in
60% of the earth's crust - melts at 1710 deg.C
- The only
other substance giving similar results to silica is boric oxide
but this also needs silica.
- Flint, quartz
and pure silica.
clays and other silicates - these all bring other oxides.