Atlas of Igneous Rocks


Igneous Rocks

Igneous rocks are rocks which solidify from molten material (magma). Cooling of the magma can occur deep beneath the surface (plutonic), beneath the surface but at relatively shallow depths (hypabyssal) or on the surface (volcanic). Igneous rocks come in a variety of forms and colors. For example two samples of granite, while mineralogically similar, may look quite different, and yet they are both granites. The links below are an attempt to show the common types of both plutonic and volcanic igneous rocks and some of the varieties that are found. It is by no means a complete list of the types and varieties that are found in the world. Click on the rock name to view a sample of that rock type.

Atlas of Igneous Rocks
Rock Name / Image Texture Composition Occurance Images
Andesite: Hornblende Andesite Porphyritic Intermediate Volcanic Close-up1
Anorthosite Phaneritic Mafic Plutonic Close-up2
Aplite Phaneritic Felsic Hypabyssal Close-up3
Basalt Aphanitic Mafic Volcanic Close-up4
Basalt: Amygdaloidal Basalt Porphyritic Mafic Volcanic Close-up5
Basalt: Olivine Basalt Porphyry Porphyritic Mafic Volcanic Close-up6
Bostonite (Trachyte Porphyry) Porphyritic Intermediate Volcanic Close-up7
Carbonatite: Siderite Carbonatite Phaneritic Ultramafic Plutonic Close-up8
Dacite Porphyritic Intermediate Volcanic Close-up9
Diabase Phaneritic Mafic Hypabyssal Close-up10
Diabase porphyry Porphyritic Mafic Hypabyssal Close-up11
Diorite Phaneritic Intermediate Plutonic Close-up11a
Diorite: Quartz Diorite (Tonalite) Phaneritic Intermediate Plutonic Close-up12
Gabbro: Hornblende Gabbro 1 Phaneritic Mafic Plutonic Close-up13
Gabbro: Hornblende Gabbro 2 Phaneritic Mafic Plutonic Close-up14
Gabbro: Olivine Gabbro Phaneritic Mafic Plutonic Close-up15
Granite: Alkalic Granite Phaneritic Felsic Plutonic Close-up16
Granite: Biotite Granite Phaneritic Felsic Plutonic Close-up17
Granite: Biotite Hornblende Granite Phaneritic Felsic Plutonic Close-up18
Granite: Muscovite-Biotite Granite Phaneritic Felsic Plutonic Close-up19
Granodiorite Phaneritic Intermediate Plutonic Close-up20
Harzburgite (Pyroxenite) Phaneritic Ultramafic Plutonic Close-up21
Ijolite Phaneritic Mafic Plutonic Close-up22
Kimberlite Porphyritic Ultramafic Volcanic
Lamprophyre Phaneritic Mafic Hypabyssal Close-up24
Latite Porphyry Porphyritic Intermediate Volcanic Close-up25
Monzonite Phaneritic Intermediate Plutonic Close-up26
Monzonite: Quartz Monzonite Porphyry Phaneritic Intermediate Plutonic Close-up27
Norite Phaneritic Mafic Plutonic Close-up28
Obsidian Glassy Felsic Volcanic Close-up29
Peridotite: Olivine Peridotite Phaneritic Ultramafic Plutonic Close-up30
Phonolite Porphyritic Intermediate Volcanic Close-up31
Pumice Frothy Felsic Volcanic Close-up32
Pyroxenite (Harzburgite) Phaneritic Ultramafic Plutonic Close-up33
Rhyolite Porphyritic Felsic Volcanic Close-up34
Rhyolite Porphyry Porphyritic Felsic Volcanic Close-up35
Rhyolite Tuff Pyroclastic Felsic Volcanic Close-up36
Scoria Scoreaceous Mafic Volcanic Close-up37
Syenite: Alkalic Syenite Phaneritic Intermediate Plutonic Close-up38
Syenite: Hornblende Syenite Phaneritic Intermediate Plutonic Close-up39
Syenite: Nepheline Syenite Phaneritic Mafic Plutonic Close-up40
Syenite: Nepheline-Sodalite Syenite Phaneritic Mafic Plutonic Close-up41
Tonalite (Quartz Diorite) Phaneritic Intermediate Plutonic Close-up42
Trachyte Porphyry Porphyritic Intermediate Volcanic Close-up43
Trachyte Porphyry (Bostonite) Porphyritic Intermediate Volcanic Close-up44