Shale
| Colour | Gray, Black, Brown |
|---|
What is Shale?
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g., kaolin, Al2Si2O5(OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. Shale is characterized by its tendency to split into thin layers (laminae) less than one centimeter in thickness. This property is called fissility. Shale is the most common sedimentary rock.
How to identify Shale
Shale in different forms
Stones often confused with Shale
Frequently asked questions
How hard is Shale?
Shale's hardness varies; see the property table above.
What colour is Shale?
Shale is typically gray, black, brown.