Density of Gabbro: Porosity, Velocity and Strength Values

The density of gabbro typically runs from 2.9 to 3.1 g/cm3, or about 2900 to 3100 kg/m3, with porosity of 0.1 to 1 percent. Compressional seismic velocity sits near 6 to 7 km/s and unconfined compressive strength spans 150 to 300 MPa. The table below collects the values; the notes explain why the ranges are as wide as they are.

PropertyTypical range
Density2.9 to 3.1 g/cm3
Porosity0.1 to 1 percent
P wave velocity6 to 7 km/s
Unconfined compressive strength150 to 300 MPa
Mass of 1 m3 (mid density)about 3.00 tonnes

Why the range

The plutonic twin of basalt: dense, tight, and consistently strong, which is why it anchors so many aggregate specifications. 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

Related Calculators and Reference