(IDEX Online) - A 126-carat "cat's eye" emerald was among the largest ever submitted for grading, said the GIA lab in Tokyo.The cabochon gemstone - shaped with a convex obverse rather than faceted - shows a pronounced chatoyant - or cat's eye - effect. That's when a band of bright light is reflected by a series of rain-like inclusions aligned within the stone."The emerald contained numerous reflective rain-like inclusions creating a chatoyant effect, whitish granular flake-like inclusions, and aggregates of tiny whitish crystals," the lab said in its winter 2022 issue of Gems & Gemology.The semi-transparent green cabochon measures 31.3mm ??- 26.2mm ??- 20.9 mm and the inclusions suggest it originated in Brazil.Pic courtesy GIA