RocksdayFlint vs Jasper
The quickest way to tell Flint from Jasper: Flint is a rock — a mix of grains or minerals; Jasper is a single mineral.
Dark nodules of microcrystalline quartz, especially the ones that grew in chalk. In North America the word is also used for any chert that was knapped into tools.
Photo: Otis Crandell, CC BY-SA 3.0
Opaque, impurity-rich microcrystalline quartz. Iron oxides give the classic brick red, but jasper comes in nearly every earthy color and pattern.
Photo: Tommy from Arad, CC BY 2.0
Quick tests
- Texture: Flint is a rock — a mix of grains or minerals; Jasper is a single mineral.
Key differences
- Jasper is opaque and colorful rather than a dark chalk nodule.
Side by side
| Property | Flint | Jasper |
|---|---|---|
| Type | Sedimentary rock | Mineral |
| Mohs hardness | 6.5–7 | 6.5–7 |
| Luster | Waxy | Dull to waxy |
| Streak | — | White |
| Colors | Black, Gray, Brown | Red, Brown, Yellow, Green |
| Crystal system / structure | Microcrystalline quartz nodules | Microcrystalline quartz (chalcedony) |
| Specific gravity | 2.5–2.7 | 2.5–2.9 |
| Formula | — | SiO₂ + impurities |
| Found in | Chalk cliffs of southern England; Northern France | Oregon and Idaho; India |
Properties that are the same for both are grayed out.
How to identify flint
- Dark gray to black nodules, often with a white chalky rind.
- Breaks in smooth curves with razor edges.
- Waxy on a fresh break, and it scratches glass.
- Sparks against steel.
Structure: Microcrystalline quartz nodules
Full Flint guide →How to identify jasper
- Completely opaque, even at thin edges.
- Solid earthy colors, often red, sometimes patterned.
- Hard — scratches glass.
- Smooth, curved fracture surfaces.
Crystal system: Microcrystalline quartz (chalcedony)
Full Jasper guide →More comparisons
Frequently asked questions
What is the difference between flint and jasper?
Flint is a sedimentary rock with a Mohs hardness of about 6.5–7 and a waxy luster, usually black, gray or brown. Jasper is a mineral with a Mohs hardness of 6.5–7 and a dull to waxy luster, usually red, brown, yellow or green.
How can you tell flint from jasper?
Flint is a rock — a mix of grains or minerals; Jasper is a single mineral. Jasper is opaque and colorful rather than a dark chalk nodule.
Could you tell them apart from a blurry close-up?
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