Geyser A rare type of hot spring that periodically discharges a fountain of hot water and steam (or sometimes just gas).

Granite Light colored, coarse grained, intrusive rock with a felsic (silica-rich) composition that is mostly made of quartz, sodium and potassium-bearing feldspar, and plagioclase. Minor...

Granitoid A generic term referring to hard, coarsely crystalline plutonic rock that is produced by intrusion of magma followed by a long period of slow cooling and solidification below the...