Density of Gypsum: Porosity, Velocity and Strength Values
The density of gypsum typically runs from 2.2 to 2.4 g/cm3, or about 2200 to 2400 kg/m3, with porosity of 1 to 5 percent. Compressional seismic velocity sits near 3.5 to 5 km/s and unconfined compressive strength spans 15 to 40 MPa. The table below collects the values; the notes explain why the ranges are as wide as they are.
| Property | Typical range |
|---|---|
| Density | 2.2 to 2.4 g/cm3 |
| Porosity | 1 to 5 percent |
| P wave velocity | 3.5 to 5 km/s |
| Unconfined compressive strength | 15 to 40 MPa |
| Mass of 1 m3 (mid density) | about 2.30 tonnes |
Why the range
Soft, soluble, and creep prone: gypsum dissolving under a foundation is a slow motion sinkhole. 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, for the conversion when your source quotes specific gravity and your spreadsheet wants density.
- Two Way Time to Depth Converter, since these velocity ranges feed straight into time to depth work.
- Density of Chalk, for the comparison that decides which unit you are actually looking at.
- Density of Andesite, for the lithology most often logged next to it.
- USGS Mineral Resources Program, published rock and mineral property data.