Frozen Opals are a very new and interesting product sold by After Midnight Art Stamps (see photo at left). It comes in a flat sheet and looks like an actual opal does. It gives a very magical feel to any piece of art you use it with.

Frozen Opals are thin slices of resin that have "opal chips" fused inside the resin. The resin itself, once heated, acts as an adhesive and "glues itself" to whatever you are heating. You can heat it in an oven or with your heat gun. The resin slice is fairly thin, so you need to make sure its temporarily affixed to a surface before hitting it with a heat gun (so it doesn't blow away before the resin melts and permanently adheres it to the surface). I've used a light double sided tape on card stock and randomly placed little pieces of the Frozen Opals across the tape (the Frozen Opals tear easily, so you can tear chunks from the larger sheet). Then you heat it with a heat gun. The resin melts and goes totally translucent, leaving the opal chips behind permanently affixed to your surface. If you like the Frozen Opals chunks look without heating it, you can leave them "as is".