Scoria
Scoria is a dark-colored, vesicular volcanic rock that forms from mafic lava. Unlike pumice, scoria is denser and sinks in water. It has a rough, cinder-like appearance and is commonly used in landscaping and as lightweight aggregate.
Physical Properties of Scoria
| Texture | Vesicular (bubbly) |
| Colors | Dark brown, black, dark red |
| Magnetism | Potentially magnetic |
| Grain Size | Fine to medium-grained |
| Hardness | 5-6 |
| Density | 1.5-2.5 g/cm³ |
Rock Identifier – AI rock expert in your pocket
Identify rocks instantly with AI-powered recognition
Chemical Properties of Scoria
Main Elements:
Si, Al, Fe, Mg, Ca, O
Chemical Composition:
SiO₂ 45-52%, Al₂O₃ 14-18%, FeO 5-14%, MgO 5-12%, CaO 8-12%, similar to basalt
Health Risk of Scoria
Scoria dust can cause respiratory irritation. Generally safe to handle, but avoid inhaling fine particles.
For more information and instant rock identification
Download the App for FreeDiscover the Value of Scoria
Market Price:
Polished: $0.10-$0.80 per piece
Raw/Tumbled: $0.50-$4 per piece
Characteristics of Scoria
Density:
1.5-2.5 g/cm³
Compressive Strength:
Low (highly porous)
Melting Point:
1000-1200°C
Formation:
Forms when gas-rich mafic lava erupts, trapping gas bubbles as the lava cools. The darker color comes from iron-rich minerals.
Composition:
Composed of volcanic glass with gas bubbles, similar in composition to basalt but with trapped gas.
Types:
- Basaltic Scoria
- Andesitic Scoria
Etymology:
Derived from the Greek word "skoria" meaning "dross" or "refuse", referring to its cinder-like appearance.
Want to identify scoria instantly?
Try our AI-powered rock identifier app
Cultural Significance of Scoria
Uses:
- Landscaping
- Lightweight aggregate
- Drainage material
- Decorative stone
Distribution:
Found in volcanic regions worldwide, especially around cinder cone volcanoes
Historical Use:
Used in construction and landscaping. Cinder cones are made entirely of scoria.
Symbolism:
Represents volcanic activity and Earth's fiery nature
Frequently Asked Questions
What is the difference between scoria and pumice?
Scoria is darker, denser, and sinks in water, while pumice is lighter, lighter in color, and floats. Scoria forms from mafic lava, pumice from felsic lava.
Where is scoria found?
Scoria is found around cinder cone volcanoes and volcanic regions worldwide, especially in areas with basaltic volcanism.
Instantly Identify Rocks with a Snap
Snap a photo for instant rock/gemstone/mineral ID and properties analysis
Identify Scoria with AI
Use the Rock Identifier app to instantly recognize scoria and other rocks with AI-powered identification.
Download App