miarolitic rock

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June 30, 2026

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Miarolitic rock is a type of igneous rock characterized by irregular cavities. Within these cavities, well-formed crystals project outwards. This structure is often found in granites. The term "miarolitic" itself originates from Italian dialect, meaning granite with small cavities. These cavities, also known as miaroles or druses, can contain crystals and are thought to form from a local concentration of gases during the final stages of the rock's consolidation.12

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igneous rock
Small-scale structural features
Miarolitic rocks are felsic phanerites distinguished by scattered pods or layers, ordinarily several centimetres in maximum thickness, within which their essential minerals are coarser-grained, subhedral to euhedral, and otherwise pegmatitic in texture. Many of these small interior bodies, called miaroles, contain centrally disposed crystal-lined cavities…
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Miarolitic rocks are felsic phanerites distinguished by scattered pods or layers, ordinarily several centimetres in maximum thickness, within which their essential minerals are coarser-grained, subhedral to euhedral, and otherwise pegmatitic in texture. Many of these small interior bodies, called miaroles, contain centrally disposed crystal-lined cavities…
Read More