Fish fossils are the mineralized remains or impressions of prehistoric fish preserved in sedimentary rock. They often appear as flattened skeletons in limestone or shale, with delicate fin details visible, and are highly prized by collectors for their anatomical detail and evolutionary significance.

Hardness

3-5

Mohs

Luster

Dull

Streak

White

Transparency

Opaque

fossilcommon

Fish Fossil

Also: Icthyolite

Hardness: 3-5
Luster: Dull
Streak: White
Transparency: Opaque

Is this fish fossil?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch fish fossil with a known reference. Fish Fossil sits at Mohs 3-5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Fish Fossil leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Fish Fossil typically shows a dull luster.
4
Match the color range
Compare against the expected color range: brown, tan, gray, black, white.
5
Look at form & habit
Typical habit: replacement or compression fossil.

Often found alongside fish fossil

Minerals reported to co-occur with fish fossil. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Mohs hardness: 3-5
Density: 2.0-2.8 g/cm³
Colors: Brown Tan Gray Black White
Streak: White
Luster: Dull
Transparency: Opaque
Crystal habit: Replacement or Compression Fossil
Cleavage: None
Rarity: Common
Uses: Collector, Decorative
Host rock: Sedimentary Rock
Typical price: $10-100 for common specimens, $500+ for museum-quality plates

Where rockhounds find fish fossil

Classic worldwide localities

Green River Formation, USA
Solnhofen Limestone, Germany
Santana Formation, Brazil
Lebanon
England

Field-hunting tip

Look in sedimentary rock country — that is the host setting where fish fossil typically forms. If you start seeing calcite, limestone, pyrite in float, you are in the right ground. Field specimens usually show a replacement or compression fossil habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify fish fossil?+

Mohs hardness is 3-5. It typically shows a dull luster. The streak is white. Common colors include brown, tan, gray, black.

Where is fish fossil found?+

Notable localities include Green River Formation, USA; Solnhofen Limestone, Germany; Santana Formation, Brazil; Lebanon; England.

How much is fish fossil worth?+

Typical asking prices fall in the range of $10-100 for common specimens, $500+ for museum-quality plates. Quality, size, and provenance can move individual specimens well outside that range.

What minerals are found with fish fossil?+

Fish Fossil commonly co-occurs with calcite, limestone, pyrite, shale. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fish fossil form in?+

Fish Fossil typically forms in sedimentary rock. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fish fossil used for?+

Fish Fossil is used in collector, decorative.

Find fish fossil on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.