Loooook into my orb. No really, check out a GIF of one of these Internal Fire Glass vortex spheres. The optical illusion is super trippy. And super... supercalifragilisticexpialidocious. Glass artist Scott Pernicka handcrafts every one of the mesmerizing globes, and never tries to make the some one twice. They're not cheap, but I'll bet it's tough to condense an entire cyclonic solar system into a palm-sized piece of desktop art, so I can't say the glass spheres are overpriced.
Pernicka employs hard borosilicate glass to achieve high clarity in his spheres, shaping it at over 3000 degrees. During the formation process he adds a combination of 99.99% pure gold, silver, crystallized metals, or metal oxides, which turn to gases under high enough heat, and create the stunning colors. Then he uses The Force to achieve the Internal Fire, and the effect of the glass spheres spiraling towards infinity.