Identification guide · Igneous Rocks
How to Identify Norite
Norite is usually black, dark gray, and white with a dull luster and is opaque. It has a Mohs hardness of 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Its streak is gray to white. It is most often confused with Basalt, Basaltic Andesite, and Trachyte; the tests below separate them.
Norite identification checklist
| Color | Black, Dark gray, White, Greenish black, Brown | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Dull | Compare a fresh surface with glass and metal; this luster is softer than either. |
| Transparency | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6 | It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. |
| Streak | Gray to white | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Variable by feldspar and pyroxene grains | |
| Fracture | Uneven to granular | |
| Specific gravity | 3 | Ordinary rock-like heft (specific gravity about 3), similar to quartz. |
Norite look-alikes and how to tell them apart
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Norite vs Basalt →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Norite vs Basaltic Andesite →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Norite vs Trachyte →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Field tips
- Look for a dense, dark, coarse-grained intrusive texture.
- Pale plagioclase and dark pyroxene can create a speckled appearance.
- Norite is visually close to gabbro, so mineral details and context matter.
- Fresh surfaces are much more useful than weathered dark exteriors.
Norite identification FAQ
How can you tell if a rock is Norite?
Check the color (black, dark gray, white, and greenish black), the dull luster, a Mohs hardness of 6 and a gray to white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Norite?
Norite has a Mohs hardness of 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
What is the difference between Norite and Basalt?
Norite (Mohs 6, dull luster) and Basalt (Mohs 6, dull luster) look alike, but hardness, streak and heft usually separate them. See the full Norite vs Basalt comparison for a side-by-side table.
Is Norite worth anything?
Entry-level Norite specimens sell for around $1, typical collector pieces about $10, and premium examples $75 or more depending on size, quality and locality.
What color is Norite?
Norite is most often black, dark gray, white, and greenish black. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
