This AAA-grade iris agate slice, precision-cut from a larger piece of high-grade rough, showcases some of the finest diffraction iridescence seen in natural agate. Sourced from Rio Grande do Sul, Brazil—arguably the most celebrated locality for this optical phenomenon—this slice displays intensely saturated bands of spectral color, especially under backlight.

The thin bands of cryptocrystalline quartz within iris agate diffract light in much the same way as a diffraction grating, producing an extraordinary rainbow effect when viewed at the right angle. This example features extremely tight, parallel banding that radiates with vivid neon greens, golds, pinks, and blues—highlighting why Brazilian iris agate is considered best in class. At 2.7mm thick, this slice is a bit more robust than typical jewelry-ready iris, making it especially suitable for bezel setting or elevated fine art inlay applications while still fully revealing the intense optical display.

An exceptional example of natural diffraction captured in stone.