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| Contents: | Top – 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |

List
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Sorted by name; initial letter means Igneous, Sedimentary or Metamorphic rocks.

### A

I Andesite – an intermediate volcanic rock
M Anthracite – a form of hard coal
### B

S Banded iron formation – a fine grained chemical sedimentary rock composed of iron oxide minerals
S Bauxite – the main ore of aluminium. It is mostly aluminium oxide.
I Basalt – grey/black fine-grained rock from lava which cooled on the surface of the Earth.
S Blue Lias – a formation of rocks, part of the Jurassic Coast World Heritage Site.
S Breccia – a sedimentary or tectonic rock composed of fragments of other, broken rocks
### C

S Chalk – a fine grained carbonate rock composed mainly of coccoliths
S Chert – a fine grained chemical sedimentary rock composed of silica
S Clastic rock – composed of fragments, or *clasts*, of pre-existing rock.
S Claystone – a sedimentary rock formed from clay
S Coal – a sedimentary rock formed from peat
S Concretion – a concretion is a rock in which a mineral cement fills the spaces between the sediment grains.
S Conglomerate – a sedimentary rock composed of large rounded fragments of other rocks
S Coquina – a sedimentary carbonate rock formed by accumulation of abundant shell fossils and fragments
### D

I Dacite – a felsic to intermediate volcanic rock with high iron content
S Diatomite – a sedimentary rock fromed from diatom fossils
I Diorite – a coarse grained intermediate plutonic rock
S Dolomite – a carbonate rock composed of calcium magnesium carbonate: CaMg(CO3)2
I Dunite – a rock made mostly of olivine
### E

Evaporite – a chemical sedimentary rock formed by accumulation of minerals after evaporation
### F

S Flint – a form of chert
I Foidolite – a plutonic igneous rock composed of >90% feldspathoid minerals
### G

I Gabbro – a coarse grained plutonic rock chemically equivalent to basalt. Plutonic = magma cooled below surface of the Earth.
M











I Granite – a coarse grained plutonic rock composed of orthoclase, plagioclase and quartz
M Granulite – a high grade metamorphic rock formed from basalt; also a facies of metamorphic rocks
M Greenschist – a generic term for a mafic metamorphic rock dominated by green amphiboles
S Greenstone – greenish sandstone; and a geologic formation in Great Britain
S Greywacke – an immature sandstone with quartz, feldspar and rock fragments within a clay matrix
S Gritstone – a coarse sandstone formed from small pebbles
### H

I Horneblendite – a mafic or ultramafic cumulate rock dominated by >90% hornblende
M Hornfels – a metamorphic rock formed by heating by an igneous rock
### I

I Ignimbrite – a fragmental volcanic rock
### K

I Kimberlite – a rare ultramafic, ultrapotassic volcanic rock and a source of diamonds
### L

S Lignite – brown coal
S Limestone – a sedimentary rock composed primarily of carbonate minerals
### M

M Marble – a metamorphosed limestone
S Marl (geology) – a limestone with a considerable proportion of silicate material
M Migmatite – a high grade metamorphic rock verging upon melting into a magma
S Mudrock – a sedimentary rock composed of clay and muds
S Mudstone – a type of mudrock
### N

I Nephelinite – a silica undersaturated plutonic rock with >90% nepheline
### O

I Obsidian – volcanic glass
S Woolite – a chemical sedimentary limestone (formed by precipitation)
### P

I Pegmatite – an igneous rock (or metamorphic rock) with giant sized crystals
I Peridotite – a plutonic or cumulate ultramafic rock composed of >90% olivine
M Phyllite – a low grade metamorphic rock composed mostly of micaceous minerals
I Plutonic rocks – intrusive rocks that crystallized from magma slowly cooling below the surface of the Earth.
I Pumice – a fine grained volcanic rock with gas bubbles inside
I Pyroclastic rocks – rocks of volcanic origin
### Q

M Quartzite – a metamorphosed sandstone typically composed of >95% quartz
### R

I Rhyolite – a felsic volcanic
### S

S Sandstone – a clastic sedimentary rock defined by its grain size
M Schist – a low to medium grade metamorphic rock
M Serpentinite – a metamorphosed ultramafic rock dominated by serpentine minerals
S Shale – a clastic sedimentary rock defined by its grain size
S Siltstone – a clastic sedimentary rock defined by its grain size
M Skarn – calcium-bearing silicate rocks of any age: a metasomatic rock
M Slate – a low grade metamorphic rock formed from shale or silts
M Steatite – Steatite or soapstone is a metamorphic rock. It has a large amount of the mineral talc.
I Syenite – a plutonic rock dominated by orthoclase feldspar; a type of granitoivolcanic rock; can be a generic term
### T

I Tonalite – a plagioclase-dominant granitoid
S Travertine – a carbonate precipitate from hot-springs.
S Tufa – a porous carbonate precipitate from ambient-temperature water
I Tuff – a fine grained volcanic rock formed from volcanic ash
### V

I Variolite
### W

S Dickstone – a matrix-supported carbonate sedimentary rock

Related pages
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* List of minerals
* Igneous rock
* Sedimentary rock
* Metamorphic rock
* Geology