Zirconia, spinel, ruby and sapphire
These stones can be fired with the clay. Depending on the colour but some may be heated up to 900° C. Please check the temperature at our website.
Hint: despite the fact that the manufacturer checks the quality of the zirconia, spinel, ruby and sapphire, some may not be able to withstand the high temperatures. So if you want to be sure, heat them up before inserting in the piece of jewellery.