4.29ct Mexican Fire Agate, Full Color and BrightnessLoose, Imperial Grade Fire Agate While seemingly subtle upon first glance in artificial light, an undertone layer of blue and purple colors create a highly unusual phenomenon that makes this 4. 29 carat Mexican fire agate radiate with a pearlescent glow in the sunlight. Due to the omnidirectional nature of the stone, this effect can be seen from a multitude of different viewing angles. Well calibrated into a near oval cabochon, not something commonly