Smoky quartz with hyalite on black tourmaline

Locale: Erongo Mountain, Namibia

Approx dimensions: 4.25 x 3 x 2"

Approx weight: 437g

** Loose piece on base

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. This piece is a bit lighter than usual with some crystal faces glassy clear, providing a window inside. Erongo smoky grows sculptural angular points with nice striations like this trio of crystals perched atop a base of black tourmaline (schorl) crystals. It has some well-formed crystals with striations, and some interesting inverted hexagonal crystal shapes. Paired with hyalite and schorl, 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. This piece has ghostly dark spots. Don’t worry, smoky quartz can't expose you to radiation—even if the hyalite turns "radioactive" green under UV light.

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.

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.

Loose piece: There is a slightly loose small schorl crystal in the base of the piece. It may dislodge with handling.