Basalts are common aphanitic igneous extrusive (volcanic) rocks. Basalts are composed of minute grains of plagioclase feldspar (generally labradorite), pyroxene, olivine, biotite, hornblende and <20% quartz.

What is made up of basalt rock?

What is Basalt? Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill.

What five minerals are commonly found in Basalt?

Basalt is a very common dark-colored volcanic rock composed of calcic plagioclase (usually labradorite), clinopyroxene (augite) and iron ore (titaniferous magnetite). Basalt may also contain olivine, quartz, hornblende, nepheline, orthopyroxene, etc.