There are quite a few different ones on the market now. Theres one called 'hollywood' thats iridescent blue - it's gorgeous. I've also seen some reds and flame orange that attract me. Good luck to you!
Mystic fire topaz is a colorless topaz that is enhanced with a patented Azotic Coating producing a permanent and stable blue-green appearance with a rainbow of color accents. The Mystic fire topaz is similar to the rainbow topaz but is enhanced in a completely different manner. Mystic fire topaz is not found in nature.