Trillions - Lab Created, Cubic Zirconias, Lab Spinels, & Nano Gems they have all been tested to 1600 degrees F.
Recommended Setting:
Fireable: Firing of these stones is possible. Test fired up to 650/1230, they retain their color and quality for 1/2 hour. Result may vary depending on the firing temperature with slight color changes of the stone possible. Precaution against thermal shock required.
The Blues are Lab Spinels, the Greens are Nanos and all the other colours are cubic zirconias.