Identification guide · Quartz Family
How to Identify Agate
Agate is usually banded, blue, and brown with a waxy luster and is translucent. It has a Mohs hardness of 7. It scratches glass and a steel knife and cannot be scratched by a steel file. Its streak is white. It is most often confused with Fire Agate, Chalcedony, and Blue Lace Agate; the tests below separate them.
Agate identification checklist
| Color | Banded, Blue, Brown, Red, Green, Gray | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Waxy | Compare a fresh surface with glass and metal; this luster is softer than either. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 7 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.6 | Ordinary rock-like heft (specific gravity about 2.6), similar to quartz. |
| Crystal system | Hexagonal |
Agate look-alikes and how to tell them apart
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Agate vs Fire Agate →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Agate vs Chalcedony →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Agate vs Blue Lace Agate →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Agate vs Dendritic Agate →
Is my Agate real?
- Hardness: real Agate sits at Mohs 7. Glass imitations are about 5.5, so genuine Agate scratches glass while a glass fake cannot.
- Bubbles: round gas bubbles under a 10x loupe mean glass or resin, never a natural stone.
- Color: dyed material concentrates color in cracks and pores; look for pigment collecting at the edges of fractures.
- Temperature: natural crystals feel cool and take longer to warm in your hand than plastic or resin.
Field tips
- Check whether the specimen's color and texture match typical Agate examples.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Agate identification FAQ
How can you tell if a rock is Agate?
Check the color (banded, blue, brown, and red), the waxy luster, a Mohs hardness of 7 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Agate?
Agate has a Mohs hardness of 7. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Agate and Fire Agate?
Agate (Mohs 7, waxy luster) and Fire Agate (Mohs 7, waxy luster) look alike, but hardness, streak and heft usually separate them. See the full Agate vs Fire Agate comparison for a side-by-side table.
How do I know if my Agate is real?
Real Agate matches the hardness listed above, shows no round gas bubbles under magnification, and does not concentrate dye in cracks. Glass and resin fakes fail at least one of those checks.
Is Agate worth anything?
Entry-level Agate specimens sell for around $5, typical collector pieces about $25, and premium examples $300 or more depending on size, quality and locality.
What color is Agate?
Agate is most often banded, blue, brown, and red. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
