Porphyritic Rhyolite

Type	Igneous Rock
Texture	Porphyritic
Origin	Extrusive/Volcanic
Chemical Composition	Felsic
Color	Light Green
Mineral Composition	Potassium Feldspar, Quartz, Sodium Plagioclase, Biotite, Hornblende
Miscellaneous	Potassium Feldspar and Quartz Phenocrysts in an aphanitic (fine-grained) groundmass
Tectonic Environment	Convergent Boundary – Andean-type subduction zones, intracontinental hot spots and rifts