Yooperlites are a variety of sodalite-rich syenite found in the Upper Peninsula of Michigan.

However, crustal heterogeneity has prevented a thorough geochemical comparison of its primary igneous building blocks—volcanic and plutonic rocks—and the processes by which they differentiate ...

Large masses of plutonic rock—such ... is believed to account directly or indirectly for many varieties of igneous rock.

Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive ...

Granite is an igneous rock made up of primarily quartz ... Formally, granite is a plutonic rock that is composed of between 10 to 50% quartz (typically semi-transparent white) and 65 to 90% ...