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
Transparency
Opaque
Is this bivalve fossil?
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 bivalve fossil with a known reference. Bivalve Fossil sits at Mohs 3-5, softer than the next harder reference, harder than the previous one.
- 2Name the organismDecide what left the fossil before worrying about the rock. Organism: Bivalves (class Bivalvia). Age: Early Cambrian to recent.
- 3Check the preservationPreservation: Valves of calcite, or calcite and aragonite. That controls the weight, the hardness and how the piece takes a polish.
- 4Read the lusterHold the specimen under a strong light. Luster: dull.
- 5Match the color rangeCompare against the expected color range: tan, brown, gray, white, cream.
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
- Luster
- Dull
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Collector, Educational, Decorative
- Host rock
- sedimentary rock
- Organism
- Bivalves (class Bivalvia)
- Age
- Early Cambrian to recent
- Preservation
- Valves of calcite, or calcite and aragonite
Where rockhounds find bivalve fossil
Classic worldwide localities
- United Kingdom
- United States
- Germany
- France
- Morocco
Field-hunting tip
Where it forms: sedimentary rock. If you start seeing calcite, quartz, pyrite in float, you are in the right ground.
Common questions
How do you identify bivalve fossil?+
Mohs hardness is 3-5. Organism: Bivalves (class Bivalvia). Preservation: Valves of calcite, or calcite and aragonite. Luster: dull. Common colors include tan, brown, gray, white.
Where is bivalve fossil found?+
Notable localities include United Kingdom; United States; Germany; France; Morocco.
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?+
Where it forms: 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.
