Igneous and metamorphic rocks make up 90–95% of the top 16 kilometres (9.9 mi) of the Earth's crust by volume. … See more

Igneous rocks can be either intrusive (plutonic and hypabyssal) or extrusive (volcanic).
Intrusive igneous rocks make up the majority of igneous rocks and are formed from magm… See more

Igneous rocks are classified according to mode of occurrence, texture, mineralogy, chemical composition, and the geometry of the igneous body.
The classification of the many types of igneous roc… See more

The Earth's crust averages about 35 kilometres (22 mi) thick under the continents, but averages only some 7–10 kilometres (4.3–6.2 mi) beneath the oceans. The continental crust is composed primarily of sedimentar… See more

• The word igneous rock means composed of fire. and is derived from the Latin root words of igni-, meaning fire, and -eous meaning composed of.
• The word volcanic rock is derived from the Latin root words of Vulcan, the … See more

• Geology portal
• List of rock types – List of rock types recognized by geologists
• Metamorphic rock – Rock that was subjected to heat and pressure… See more