Hyalite Opal on Smoky Quartz – Erongo Mountains, Erongo Region, Namibia
This unusual specimen combines two visually and structurally distinct minerals: a sharply terminated smoky quartz crystal hosting a coating of hyalite opal. Under normal light, the hyalite appears nearly clear with a slight greenish tint, but under UV illumination, it fluoresces an intense neon green—a defining trait of hyalite caused by trace uranium content.
Hyalite opal is an amorphous form of silica with high water content, forming as a secondary mineral in volcanic and hydrothermal environments. In this piece, the opal has formed botryoidal (grape-like) growths on the crystal faces of the quartz, partially enveloping the termination. This pairing is rare and highly collectible, as hyalite commonly forms in drusy coatings or nodules, but rarely on top-quality quartz crystals.
The host, a smoky quartz crystal, likely developed in a pocket environment within the Erongo pegmatites, which are known for producing an array of well-crystallized minerals. Namibia’s Erongo Mountains have long been a source of exceptional mineral specimens, but combinations like this—where a strongly UV-reactive mineral coats an already desirable host—are both geologically fascinating and visually spectacular.
This specimen offers a striking contrast between clarity and opacity, structure and amorphousness, light absorption and fluorescence—making it a standout for both mineral collectors and those interested in fluorescence or rare mineral associations
51 x 21 x 20 mm
Estimate: $165 - $175
