RocksdayNovaculite vs Quartzite
How to tell them apart
An extremely fine, dense quartz rock famous as a whetstone.
Photo: James St. John, CC BY 2.0
Sandstone fused by metamorphism into an extremely hard rock of interlocked quartz grains.
Photo: Gabriel Haute Maurienne, CC BY-SA 4.0
Key differences
- Quartzite has visible sugary grains.
Side by side
| Property | Novaculite | Quartzite |
|---|---|---|
| Type | Sedimentary rock | Metamorphic rock |
| Mohs hardness | 7 | 7 |
| Luster | Waxy | Sugary to glassy |
| Colors | White, Gray, Black | White, Pink, Gray |
| Crystal system / structure | Dense microcrystalline quartz | Interlocking quartz grains (non-foliated) |
| Specific gravity | 2.6–2.65 | 2.6–2.7 |
| Found in | Ouachita Mountains, Arkansas; Texas | Baraboo, Wisconsin; Sioux Falls, South Dakota |
Properties that are the same for both are grayed out.
How to identify novaculite
- White to gray, smooth and waxy.
- Very hard; breaks with sharp edges.
- No visible grains.
Structure: Dense microcrystalline quartz
Full Novaculite guide →How to identify quartzite
- Breaks through the grains, not around them.
- Scratches glass.
- Smooth, sugary surface — not gritty.
- Doesn't fizz in acid.
Structure: Interlocking quartz grains (non-foliated)
Full Quartzite guide →More comparisons
Could you tell them apart from a blurry close-up?
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