Concretion
A variety of Sedimentary
What is Concretion?
Concretion refers to a geological formation characterized by a hard compact mass found in sediments or sedimentary rocks. It occurs through the precipitation of mineral cement, often nucleating around a pebble, fossil, or organic matter. Due to its characteristic shape, this material was often misunderstood and mistaken for fossilized eggs, turtle shells, bones, or even extraterrestrial debris.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Concretion before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Concretion Localities Map
See where Concretion is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
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Quick Facts
Physical Properties
- Color
- Various colors, often brown, grey, black, red, yellow
Also Known As
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Concretion FAQs
How do I identify Concretion?
Concretion can be identified by its Various colors color. Look for these key characteristics when examining specimens.
What color is Concretion?
Concretion typically appears in Various colors, often brown, grey, black, red, yellow. Color can vary depending on impurities and formation conditions.
