Andesite

Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende.

Icelandite is a type of volcanic rock, an andesite that is enriched in iron but deficient in aluminium (2) content greater than 60%.