Black Amethyst
Black Amethyst is silicate (quartz variety), SiO₂ + hematite micro-inclusions. In the hand, it rates 7 on the Mohs scale, and it runs deep purple-black and near-black with violet flashes in light. Amethyst so saturated with iron inclusions it reads near-black, until strong light reveals deep violet glints inside the crystals. Notable: Uruguay (Artigas, the classic deep material), Brazil.
The geology.
Black Amethyst carries the formula SiO₂ + hematite micro-inclusions. It belongs to the trigonal system. Catalogues list it as silicate (quartz variety).
It sits at 7 on the Mohs scale. The surface reads vitreous. Light behaviour is translucent to nearly opaque. Specific gravity runs 2.65. The streak is white. It breaks with conchoidal fracture, no cleavage.
Amethyst so saturated with iron inclusions it reads near-black, until strong light reveals deep violet glints inside the crystals.
It reaches buyers as clusters, points, polished freeforms or druzy slabs.
The origins.
Notable: Uruguay (Artigas, the classic deep material), Brazil.
On value, the database notes: mid-range; deep Uruguayan clusters command premiums.
Traditional associations.
In energy work traditions, associated with protection paired with intuition.
We keep this section because people ask. It sits below the geology on purpose, and none of it describes something the stone does.
Spotting the real thing.
Amethyst so saturated with iron inclusions it reads near-black, until strong light reveals deep violet glints inside the crystals.
Some 'black amethyst' is lab-irradiated quartz, genuine material flashes purple under strong light.
| Looks like | How to tell them apart |
|---|---|
| Irradiated black quartz (morion-style) | Lab-irradiated points are uniformly jet with no purple flash even backlit |
| Black obsidian | Glass with conchoidal chips, no crystal faces |
| Smoky amethyst | Smoky amethyst shows distinct brown smoke plus violet; black amethyst is dense purple-black |
At-home tests.
Before anyone talks you into a lab report, these are the checks worth doing yourself on black amethyst.
| Test | What you should see |
|---|---|
| By eye | Strong backlight reveals violet, not brown or jet |
| Scratch check | Scratches glass (Mohs 7) |
| By eye | Natural druzy crystal faces |
If these checks leave you unsure, that is what appraisers are for. Do not file, heat or soak a piece to find out.
Care & handling.
At 7 on the Mohs scale it stands up to everyday wear. It will still chip on a hard knock, so treat edges and points with respect.
It breaks with conchoidal fracture, no cleavage, which is worth knowing before you set it or drop it.
Most damage happens during cleaning, not wearing. Avoid steamers, ultrasonic tanks and anything from under the sink.
A deeper look.
Extended detail on composition, sourcing, authentication and market value.
The physical record
The formula on record is SiO₂ + hematite micro-inclusions. Crystal system: Trigonal. Specific gravity: 2.65. Streak: White. Cleavage and fracture: Conchoidal fracture, no cleavage.
How it reaches the market
Notable: Uruguay (Artigas, the classic deep material), Brazil.
What it gets confused with
Irradiated black quartz (morion-style): Lab-irradiated points are uniformly jet with no purple flash even backlit. Black obsidian: Glass with conchoidal chips, no crystal faces. Smoky amethyst: Smoky amethyst shows distinct brown smoke plus violet; black amethyst is dense purple-black.
What it is worth
Mid-range; deep Uruguayan clusters command premiums.
Where buyers get caught
Some 'black amethyst' is lab-irradiated quartz, genuine material flashes purple under strong light.
One more thing
Uruguay's basalt geodes grow the world's darkest amethyst, iron-rich fluids pushed the purple nearly to black.
An education-first guide.
There is nothing to buy on this page. Black Amethyst is not part of our catalogue, and the guide is here anyway because somebody searching the name deserves a straight answer.
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