Mexican fire opal is an interesting variety of opal with its base material ranging from nearly clear to yellow then from orange through burnt-orange or almost red. Rarer material will have the familiar flashes of color in it like Australian opal but most is the more common variety that is just yellow or orange. The appeal of this material besides a pleasing variety of colors is the high refractive index which produces cut stones with a lot of flash and brilliance. Stones with top color flash (purple, blue and green) will sell for upwards of $500/ct.