Specimen at a glance
| Mineral | Quartz (var. smoky) |
|---|---|
| Chemistry | SiO2 |
| Mohs hardness | 7 |
| Crystal system | Trigonal |
| Form | Crystal point |
| You receive | The exact specimen pictured |
About this specimen
Smoky quartz is a natural brown-to-gray variety of quartz (silicon dioxide, SiO₂) that gets its color from natural background irradiation acting on trace aluminum impurities trapped in the crystal lattice as it grew — no dye, heat, or artificial treatment involved. This point is double-terminated, meaning it formed with a pointed face on both ends rather than just one. That habit usually develops when a crystal grows freely inside a pocket of clay or matrix instead of being attached at its base to host rock, so both ends are free to crystallize. Double-terminated points turn up far less often than single-terminated ones and are especially sought after by collectors for their symmetry.
At Mohs hardness 7, quartz is tough enough for regular handling and display; just keep it away from hard knocks that could chip a termination, and wipe clean with a soft dry cloth. This is a genuine, untreated natural crystal — not lab-grown or reconstituted — so expect the individual character (small inclusions, slight asymmetry, natural growth lines) that comes with a real mineral specimen rather than a manufactured piece.
A good size for a desk, windowsill, or display shelf, and an easy way to add an uncommon crystal habit to a growing collection.
Inside the Quartz Crystal
One mineral species, a thousand looks — quartz is the shape-shifter of the mineral world.
The story: Quartz is the second most abundant mineral in Earth’s crust, and it crystallizes in nearly every rock-forming environment on the planet — which is exactly why it shows up in this shop as clear points, milky clusters, smoky towers, ghostly phantoms, and druzy-crusted matrix, all built from the same simple formula.
Why collectors chase it: Because one species covers this much ground: a single collection can hold a dozen genuinely different-looking quartz pieces without ever repeating a mineral. Phantom growth lines, smoky color zoning, and druzy crusts each record a different chapter of how that particular crystal grew.
Care: Quartz shrugs off scratches and most chemicals at Mohs 7, but avoid sudden temperature swings (a hot dishwasher after a cold shelf can crack a large piece) and clean with a soft, dry cloth.
Smoky quartz: the science
- The brown-to-black color is built by radiation, not dye. Heat it to a few hundred degrees and the color bleaches out.
- Smoky quartz commonly forms in granites and pegmatites, rocks that carry small amounts of radioactive potassium, uranium, and thorium.
- Double-terminated points like this grew free of a wall or were broken and healed, giving a point at each end.
Go deeper
Want the full story on smoky quartz: how it forms, how to identify it, and what makes a great specimen?
Questions about this piece
What is smoky quartz?
Smoky quartz is ordinary quartz darkened by natural radiation. Trace aluminum in the crystal plus gamma rays from surrounding rock create color centers that absorb light.
How hard is it, and how should I care for it?
It rates 7 on the Mohs scale. Mohs 7 and durable. Keep it out of long, direct sunlight to protect the color, and store it so the points do not knock against other stones.
Is this the exact piece I will receive?
Yes. This listing was photographed individually, and you receive the exact piece shown in the photos.
