basalt stone properties
Basalt is an igneous (volcanic) rock that is low in silica content, dark in colour, and relatively rich in iron and magnesium.
Some basalts are completely vitreous (tachylytes), and many are fine-grained and compact. However, it is typical for them to exhibit a porphyry structure, with larger crystals (phenocrystals) of olivine, auget, or feldspar in a microcrystalline matrix (earth mass)....