Dacite

Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclasefeldspar and quartz.

Dacite is relatively common, occurring in many tectonic settings. It is associated with andesite and rhyolite as part of the subalkalinetholeiitic and calc-alkaline magma series.