Syenogranite is a fine to coarse grained intrusive igneous rock of the same general composition as granite. They are characteristically felsic. The feldspar component of syenogranite is predominantly alkaline in character (usually orthoclase). For example, the syenogranite in the Salmon Mountains in Idaho is pink to tan and composed of 45–55% alkali feldspar, 15–20% plagioclase, 15–20% quartz, 5–8% biotite, 3–5% hornblende, and accessory magnetite (Evans and Green, 2003).