Basalt is a type of extrusive igneous (volcanic) rock that is low in silica concentration, has a dark color, and is relatively rich in iron and magnesium. Many basalts are incredibly fine-grained and compact, and some are almost glassy (tachylytes).
Many basalts are extremely fine-grained and compact, and others are even glassy (tachylytes). Porphyritic structure, in which bigger crystals (phenocrysts) of olivine, augite, or feldspar are embedded in a finely crystalline matrix, is far more common (groundmass).
The most prevalent porphyritic minerals in basalts are olivine and augite, with plagioclase feldspars also occurring in this form. Spongy or pumiceous basaltic lavas are common because secondary minerals like calcite, chlorite, and zeolites fill the steam voids.
To know more about Basaltic igneous rocks:
https://brainly.com/question/1143409
#SPJ4
