RocksdayAgate vs Jasper
How to tell them apart
Banded chalcedony — quartz made of microscopic crystals — that fills cavities in volcanic rock layer by layer. Light passes through the bands when held up to the sun.
Photo: James St. John, CC BY 2.0
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
Key differences
- Jasper is fully opaque; agate glows when you shine a flashlight through it.
- Agate is translucent and banded; jasper blocks light.
Side by side
| Property | Agate | Jasper |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 6.5–7 | 6.5–7 |
| Luster | Waxy to vitreous | Dull to waxy |
| Streak | White | White |
| Colors | Red, Orange, White, Gray, Brown, Blue | Red, Brown, Yellow, Green |
| Crystal system | Microcrystalline quartz (chalcedony) | Microcrystalline quartz (chalcedony) |
| Specific gravity | 2.58–2.64 | 2.5–2.9 |
| Formula | SiO₂ | SiO₂ + impurities |
| Found in | Lake Superior shores; Rio Grande do Sul, Brazil | Oregon and Idaho; India |
Properties that are the same for both are grayed out.
How to identify agate
- Concentric or parallel bands, often in red, orange and white.
- Translucent at the edges when backlit.
- Waxy surface on rough, weathered pieces ('pitted' rind).
- Hard enough to scratch glass.
Crystal system: Microcrystalline quartz (chalcedony)
Full Agate 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
Could you tell them apart from a blurry close-up?
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