Silica-rich lava hardens before flowing far, forming a dense-texture rock of tiny crystals or glass. Basic lava flows further before it solidifies, giving rise to coarse-grained igneous rock, such as granite or gabbro. In many eruptions, lava is ejected with such force that it fragments in the atmosphere, hardens while airborne, and lands to form thick layers of volcanic tuff and related pyroclastic rock.
The word lava is from the Italian word for stream, which is derived from the Latin verb lavare – to wash.
Related category GEOLOGY AND PLANETARY SCIENCE
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