This dazzling 3.7 ct freeform cabochon, measuring 11.6mm x 8.3mm x 3mm, is a top-tier example of iridescent andradite garnet from the legendary San Pedro Mountain locality in Santa Fe County, New Mexico — the only known deposit in the United States that yields andradite with this rare and captivating optical phenomenon.

Displaying razor-sharp, spectral-grade diffraction with a stunning chatoyant effect, this stone exhibits vivid bands of electric blue, ultraviolet-lilac, emerald green, and solar-gold — layered with prismatic brilliance like a moving aurora frozen in stone. The tight lamellar twinning planes responsible for this effect interact with light like a diffraction grating, producing the signature “rainbow cat’s eye” glow that shimmers as the angle shifts.

This piece captures the full magic of the locality in miniature form — a living spectrum sealed inside one of the rarest garnet phenomena on Earth.