Identifying fossils is a skill anyone can pick up. Most fossils people find are common marine creatures — shells, corals, and the occasional tooth — and once you know what to look for, they start appearing everywhere. Here's the simple method, plus how to confirm your find instantly.
Step 1 — Look for biological structure
The single best clue is organised structure that rocks don't have:
- Symmetry — two matching halves, like a clam or a leaf.
- Repeating patterns — ribs, segments, chambers or ridges.
- Recognisable shapes — spirals (ammonites), cones (horn coral), teeth, or bone.
- Texture that stands out from the surrounding rock (the matrix).
If a shape looks too deliberate to be random, you're probably holding a fossil.
Step 2 — Check the rock it's in
Fossils form almost exclusively in sedimentary rock — limestone, shale, sandstone and mudstone — because those built up in gentle layers that could preserve life. You'll rarely find fossils in igneous rock (granite, basalt) or heavily metamorphosed rock. Finding your specimen in a limestone cliff or shale bank is a strong hint. Not sure of the rock type? See rock identifier.
Step 3 — Confirm it with a photo
Once you suspect a fossil, confirm it in seconds:
Photograph the detailed face with raking side light to bring out structure.
Tap Identify. The app surveys the morphology, traces sutures and ornamentation, and cross-references reference collections.
Read the verdict. It tells you whether it's a fossil, names the species, and gives its geological age.
Confirm your fossil now
Settle "fossil or rock?" and learn its age — free on iPhone and iPad.
Download freeHow old is my fossil?
Age comes from the species and the rock layer. Once the app identifies your fossil, its geological range pins down the era — an ammonite is Mesozoic, a trilobite is Paleozoic, a horn coral spans the Ordovician to Permian (roughly 250–490 million years ago). You're literally holding deep time.
Common fossils and their look-alikes
- Ammonite vs. ammonite-shaped rock — real ones show chambered internal walls (sutures).
- Shark tooth vs. black pebble — teeth have a glossy enamel crown and a distinct root.
- Brachiopod vs. plain stone — look for the paired, ribbed shell halves.
- Crinoid stems vs. beads — button-like discs stacked in a column.
Where to look for fossils
Beaches with eroding cliffs, road cuttings, quarry spoil heaps, riverbanks and stony fields are prime hunting grounds. Always collect responsibly, follow local rules, and never dig into unstable cliffs.
Frequently asked
How can I tell if a rock is a fossil for free?
Use the structure and rock-type clues above, then confirm with a free photo scan in the app.
What's the most common fossil to find?
Marine shells — brachiopods, bivalves and ammonites — and corals top the list in most regions. See fossil identifier for the full lineup.