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 — that is 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
How do you identify ammolite?+
Where is ammolite found?+
How much is ammolite worth?+
What rocks look like ammolite?+
What minerals are found with ammolite?+
What kind of rock does ammolite form in?+
What is ammolite used for?+
Find ammolite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
