Ammolite is a rare, iridescent, gem-quality material formed from the fossilized shells of extinct ammonites found primarily in Alberta, Canada. Collectors look for vibrant, multi-colored flashes that shift as the specimen is rotated. It is often found as fragments or whole ammonite shells embedded within dark marine shale.
Is this ammolite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch ammolite with a known reference. Ammolite sits at Mohs 3.5-4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ammolite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Ammolite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: iridescent red, green, gold, blue, violet.
- 5Look at form & habitTypical habit: fossilized ammonite shell segments.
Often confused with
Ammolite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Labradorite is the harder of the two (Mohs 6-6.5 vs. 3.5-4.5); luster reads pearly on Ammolite and vitreous on Labradorite.
How to tell apart: Opal is the harder of the two (Mohs 5.5-6.5 vs. 3.5-4.5); luster reads pearly on Ammolite and vitreous on Opal.
Often found alongside ammolite
Minerals reported to co-occur with ammolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 3.5-4.5
- Density
- 2.6-2.8 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Opaque
- Crystal habit
- Fossilized Ammonite Shell Segments
- Cleavage
- None
- Rarity
- Rare
- Uses
- Gemstone, Jewelry, Collector
- Host rock
- Shale
- Typical price
- $50-500 thumbnail, $500-5000+ cabinet specimen
Where rockhounds find ammolite
Classic worldwide localities
- Bearpaw Formation, Alberta, Canada
Field-hunting tip
Look in shale country, the host setting where ammolite typically forms. If you start seeing siderite, pyrite, calcite in float, you are in the right ground. Field specimens usually show a fossilized ammonite shell segments habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find ammolite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
