Are crystals oven-safe?

I was planning on making a pair of earrings using Polymer clay and some crystals (Jolee's Jewels, from Micheals). There would be the eye pin thing that's attached to the earring finding, then two crystals, then the polymer clay bead. I was hoping to be able to bake them all together, but I'm afraid the crystals/findings will melt in the oven. Will they?