Excellent hyalite on matrix, "Mermaid's Caviar"

Locale: Erongo Mountain, Namibia

Approx dimensions: 4.5 x 3.25 x 2"

Approx weight: 383g

This is one of my favorite specimens of Erongo hyalite, absolutely thick with glossy botryoidal growth. You're going to need to buy it before I decide to keep it.

The piece is a rough aggregate of minerals appearing to contain albite, schorl (black tourmaline), and smoky quartz. The front of the matrix is nearly entirely covered by luscious large spheres of hyalite, with one large schorl crystal partially exposed.

Hyalite is a form of opal, which in turn is part of the broader quartz family. Hyalite displays botryoidal growth (bunches of “grape-like” round crystals) with a glossy high luster like a layer of bubbles. Hyalite can appear fluid with formations that look like the splash from a drip frozen in place, or as if the edge has been peeled up away from the quartz like a tutu. I think it looks like mermaid caviar, and this one is the mother lode!

UV reactivity Hyalite is so strongly UV reactive that you can see it in sunlight. Under indoor lighting it is pale yellow to golden in color, but turns visibly greenish yellow when exposed to the UV in sunlight. 395nm UV fluoresces a strong green, with a light blue undertone especially in thinner areas of hyalite (but it is mostly thick on this piece!). 365nm UV fluoresces a strong yellowish-green color, generally visible even in bright lighting. No phosphorescence detected.