What is difference between Basalt and Gabbro?

Gabbro is coarse grained while basalt is fine grained. Gabbro is sometimes called “black granite” for it too is coarse-grained, but a large proportion of iron-bearing minerals make gabbro heavier and dark colored. Gabbro can also be gray or light green. Granite is a coarse-grained igneous rock with average grain size ranging from 1 to 25 millimeters. Gabbro is generally coarse grained, with crystals in the size range of 1 mm or greater. Therefore, Gabbro is a dense, mafic intrusive rock closer to granite than basalt.