RocksdayAgate vs Fire Agate
To tell Agate from Fire Agate: Ordinary agate is banded but doesn't flash rainbow colors.
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
Brown chalcedony layered with thin films of iron oxide that flash red, green and gold when the stone is tilted.
Photo: Maricopa Mining LLC, CC BY-SA 3.0
Key differences
- Ordinary agate is banded but doesn't flash rainbow colors.
Side by side
| Property | Agate | Fire Agate |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 6.5–7 | 6.5–7 |
| Luster | Waxy to vitreous | Vitreous to waxy |
| Streak | White | White |
| Colors | Red, Orange, White, Gray, Brown, Blue | Brown, Orange, Red, Green |
| Crystal system | Microcrystalline quartz (chalcedony) | Microcrystalline quartz (chalcedony) |
| Specific gravity | 2.58–2.64 | 2.6–2.7 |
| Formula | SiO₂ | SiO₂ |
| Found in | Lake Superior shores; Rio Grande do Sul, Brazil | Slaughter Mountain, Arizona; Deer Creek, Arizona |
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 fire agate
- Brown or orange body color with patches of iridescence.
- Waxy, and hard enough to scratch glass.
- The color sits in curved layers, not in round opal dots.
Crystal system: Microcrystalline quartz (chalcedony)
Full Fire Agate guide →More comparisons
Frequently asked questions
What is the difference between agate and fire agate?
Agate is a mineral (SiO₂) with a Mohs hardness of 6.5–7 and a waxy to vitreous luster, usually red, orange, white, gray, brown or blue. Fire Agate is a mineral (SiO₂) with a Mohs hardness of 6.5–7 and a vitreous to waxy luster, usually brown, orange, red or green.
How can you tell agate from fire agate?
Ordinary agate is banded but doesn't flash rainbow colors.
Could you tell them apart from a blurry close-up?
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