Density of Schist: Porosity, Velocity and Strength Values
The density of schist typically runs from 2.5 to 2.9 g/cm3, or about 2500 to 2900 kg/m3, with porosity of 1 to 3 percent. Compressional seismic velocity sits near 4 to 5.5 km/s and unconfined compressive strength spans 20 to 100 MPa. The table below collects the values; the notes explain why the ranges are as wide as they are.
| Property | Typical range |
|---|---|
| Density | 2.5 to 2.9 g/cm3 |
| Porosity | 1 to 3 percent |
| P wave velocity | 4 to 5.5 km/s |
| Unconfined compressive strength | 20 to 100 MPa |
| Mass of 1 m3 (mid density) | about 2.70 tonnes |
Why the range
Mica rich foliation makes schist the classic anisotropic problem rock: strong numbers from cores, sliding failures along foliation in cuts. For design work, treat these as screening values: a specific site deserves specific testing, and the calculators linked below show how each number is measured and used.
Use these values
- Rock Density Calculator to build density from mineral composition.
- Porosity Calculator to measure porosity from well logs.
- The Property Library for every rock, soil, and mineral on this site.
Related Calculators and Reference
- Rock Density and Specific Gravity Calculator, to turn a specific gravity straight into a density in whichever unit the report wants.
- Two Way Time to Depth Converter, because the velocity quoted here is what a time to depth conversion runs on.
- Density of Gneiss, for the lithology most often logged next to it.
- Density of Limestone, for the neighbouring rock type in the same section.
- USGS Mineral Resources Program, published rock and mineral property data.