Siltstone
A variety of Sedimentary

What is Siltstone?
Siltstone is a clastic sedimentary rock composed of fine-grained particles, primarily silt-sized. It belongs to the mudrock category, characterized by a relatively low amount of clay minerals and lacking the ability to split into thin layers like shale. It forms in various environments, including riverbeds, lakes, and oceans.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Siltstone 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.
Siltstone Localities Map
See where Siltstone 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
- Gray, red, green, yellow, brown, etc.
- Hardness (Mohs)
- 6 - 7
- Density
- 2.2 - 2.8 g/cm³

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Siltstone FAQs
How do I identify Siltstone?
Siltstone can be identified by its hardness of 6 - 7 on the Mohs scale, Gray color. Look for these key characteristics when examining specimens.
What color is Siltstone?
Siltstone typically appears in Gray, red, green, yellow, brown, etc.. Color can vary depending on impurities and formation conditions.
How hard is Siltstone?
Siltstone has a hardness of 6 - 7 on the Mohs scale. This gives it moderate hardness.


