Smoky quartz pair with hyalite, needle formation

Smoky quartz pair with hyalite, needle formationLocale: Erongo Mountain, Erongo Region, Namibia Approx dimensions: 4 x 1. 75 x 1. 75" Approx weight: 202g Smoky quartz from the Erongo region is typically a quite dark brown black color, with lower clarity due to natural inclusions, and a flat surface luster caused by etching. It can grow blocky points like the larger crystal in this pair. The two points have nice angular structure on one side and a thick layer of hyalite on the other. Paired with

Locale: Erongo Mountain, Erongo Region, Namibia

Approx dimensions: 4 x 1.75 x 1.75"

Approx weight: 202g

Smoky quartz from the Erongo region is typically a quite dark brown-black color, with lower clarity due to natural inclusions, and a flat surface luster caused by etching. It can grow blocky points like the larger crystal in this pair. The two points have nice angular structure on one side and a thick layer of hyalite on the other. Paired with hyalite, the smoky quartz takes on a witchy appearance.

Smoky quartz gets its dark coloration from trace elements that tint dark when the quartz is exposed to natural radiation. Don’t worry, the specimen can't expose you to radiation—even if the hyalite turns "radioactive" green under UV light due to trace elements of uranium.

Hyalite is a form of opal, which in turn is part of the broader quartz family. Related minerals commonly grow together because they have similar requirements for growth: in this case, the availability of silica that is the basis for the quartz family. Growing conditions that initially produced quartz changed, and a later generation of growth deposited the less common hyalite on the specimen.

Hyalite displays botryoidal growth (bunches of “grape-like” round crystals) with a glossy high luster like a layer of bubbles. I think it looks like mermaid caviar! 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, like seen on the larger point. In the nook between the two points, there is an interesting formation of small needles made of round forms growing from the botryoidal hyalite, which may be hyalite. On other specimens it takes on a purple amethyst hue on the ends, possibly another shift in growing conditions causing a transition from hyalite to a different type of quartz.

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 an icy blue undertone. Best viewed in darker conditions. 365nm UV fluoresces a strong yellowish-green color, generally visible even in bright lighting. No phosphorescence detected.