Synthetic spinel, jewelery quality. Oval cut and safe to fire directly in the clay.
This stone can be set in silver clay and fired in an kiln, with a microtorche or on the gas stove. The stones have been tested for 30 minutes at 850°C.
Set in copper or bronze clay, it can be fired for 4 hours in activated carbon at 850°.
Preferably place large stones in a cold kiln and allow them to cool down in the kiln after firing. Temperature fluctuations can cause the stone to crack.
Do not cool in water, the stone will crack due to the shock.
A hole under the stone ensures that the shrinkage of the clay is better distributed during firing. Otherwise it is possible that the stone will crack or become dull during firing.
A hole under the stone also allows light to enter so that the stone is much more lively.
Make sure that the clay encloses the stone properly, otherwise it can be pushed out during firing.
Clean the stone well before firing, it is not possible to remove the silver after firing. Use a wooden skewer for this.
