Nundorite as an Ornamental Gem Material.

This article focuses on nundorite, an ornamental gem material found exclusively at Nundora Station in northwestern New South Wales, Australia. Nundorite is a fine-grained, granoblastic rock with a light- to medium-brown matrix and distinctive pale green aegirine porphyroblasts, valued for its aesthetic qualities rather than transparency. Geochemically, it is a highly fractionated phonolite enriched in rare metals such as zirconium, hafnium, niobium, tantalum, and rare-earth elements. Characterized cabochons of nundorite exhibit vitreous to sub-vitreous luster, specific gravity values between 2.49 and 2.53, no reaction to the Chelsea Colour Filter, and inertness to UV radiation. While primarily used decoratively and in building, nundorite’s unique colors and textures make it notable as an ornamental gem when cut and polished.