Bivalve fossils are the mineralized remains of mollusks, characterized by two matching hinged shells. They are frequently found in sedimentary layers and are often preserved as casts, molds, or replaced by silica or calcite through permineralization.

Hardness

3-5

Mohs

Luster

Dull

Streak

White

Transparency

Opaque

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Bivalve Fossil

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

Is this bivalve 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 bivalve fossil with a known reference. Bivalve 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. Bivalve Fossil leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Bivalve Fossil typically shows a dull luster.
4
Match the color range
Compare against the expected color range: tan, brown, gray, white, cream.
5
Look at form & habit
Typical habit: bivalved shells.

Often found alongside bivalve fossil

Minerals reported to co-occur with bivalve 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: 2.0-2.7 g/cm³
Colors: Tan Brown Gray White Cream
Streak: White
Luster: Dull
Transparency: Opaque
Crystal habit: Bivalved Shells
Cleavage: None
Rarity: Common
Uses: Collector, Educational, Decorative
Host rock: Sedimentary Rock
Typical price: $5-50 depending on preservation and size

Where rockhounds find bivalve fossil

Classic worldwide localities

United Kingdom
United States
Germany
France
Morocco

Field-hunting tip

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

Common questions

How do you identify bivalve fossil?+

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

Where is bivalve fossil found?+

Notable localities include United Kingdom; United States; Germany; France; Morocco.

How much is bivalve fossil worth?+

Typical asking prices fall in the range of $5-50 depending on preservation and size. Quality, size, and provenance can move individual specimens well outside that range.

What minerals are found with bivalve fossil?+

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

What kind of rock does bivalve fossil form in?+

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

What is bivalve fossil used for?+

Bivalve Fossil is used in collector, educational, decorative.

Find bivalve fossil on the map

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