Specific oxides needed in ceramic glazes can be subject to vaporization (and therefore lost up the chimney of the kiln) if firing proceeds to long or too high.
Between the melting and boiling points (and, of course, especially while boiling is proceeding) all glaze compounds vaporize to some extent. The amount of vaporization is related to the time and temperature and atmosphere of the firing. Obvious examples of cases where vaporization must be considered are chrome, zinc, fluorine sourcing materials.
The firing of fluorine containing materials (e.g. frits) must proceed quickly to minimize the loss and get the benefit of their presence. Zinc vaporizes in reduction atmospheres. Another example is bismuth compounds, they source the very low melting oxide, that, if fired too high could vaporize. The reason this is a concern is because bismuth is very very expensive.
Volatilization is not the same as vaporization. The former refers to oxides within materials that burn off, and are expected to burn off during firing (e.g. carbon, H2O). The term "flashing" can refer to vaporization (e.g. chrome flashing).
|Oxides||F - Fluorine|