Basalt is an extrusive igneous rock. It is the bedrock of the ocean floor and also occurs on land in extensive lava flows. read more
Basalt underlies more of Earth's surface than any other rock type. Most areas within Earth's ocean basins are underlain by basalt. Although basalt is much less common on continents, lava flows and flood basalts underlie several percent of Earth's land surface. read more
Physical Properties of Basalt Physical properties of rocks are used to identify the type of rocks and to discover more about them. There are various physical properties of Basalt like Hardness, Grain Size, Fracture, Streak, Porosity, Luster, Strength etc which defines it. read more
The term basalt is at times applied to shallow intrusive rocks with a composition typical of basalt, but rocks of this composition with a phaneritic (coarser) groundmass are generally referred to as diabase (also called dolerite) or, when more coarse-grained (crystals over 2 mm across), as gabbro. read more