TOP TEN

TOP TEN / / ROCKS.

  
Dictionary definition:


- Relatively hard, naturally formed mineral or petrified matter; stone.

- A relatively small piece or fragment of such material.  A relatively large body of such material, as a cliff or peak.

- A naturally formed aggregate of mineral matter constituting a significant part of the earth's crust.

- One that is similar to or suggestive of a mass of stone in stability, firmness, or dependability: The family has been his rock during this difficult time.

Wiki definition:

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.

The Earth's outer solid layer, the lithosphere, is made of rock. In general, rocks are of three types, namely igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, and petrology is an essential component of geology.

Different types of rock:

Web sourced:

Igneous

Andesite - an Intermediate volcanic rock

Anorthosite - an igneous ultramafic rock composed predominantly of plagioclase

Aplite - a very fine grained intrusive igneous rock

Basalt - a volcanic rock of mafic composition

Adakite - a class of basaltic rocks containing relatively small amounts of the trace elements yttrium and ytterbium

Hawaiite - a class of basalts formed from Ocean Island (hot spot) magmatism

Basanite - a volcanic rock of mafic composition; essentially a silica undersaturated basalt

Boninite - a high-magnesian basalt dominated by pyroxene

Carbonatite - a rare igneous rock composed of >50% carbonate minerals

Charnockite - a type of granite containing pyroxene

Enderbite - a variety of charnockite

Dacite - a felsic to intermediate volcanic rock with high iron content

Diabase or dolerite - an intrusive mafic rock forming dykes or sills

Diorite - a coarse grained intermediate plutonic rock composed of plagioclase, pyroxene and/or amphibole

Dunite - an ultramafic cumulate rock composed of olivine and accessories

Essexite - a silica undersaturated mafic plutonic rock (essentially a foid-bearing gabbro)

Foidolite - a plutonic igneous rock composed of >90% feldspathoid minerals

Gabbro - a coarse grained plutonic rock composed of pyroxene and plagioclase basically equivalent to basalt

Granite - a coarse grained plutonic rock composed of orthoclase, plagioclase and quartz

Granodiorite - a granitic plutonic rock with plagioclase > orthoclase

Granophyre - a subvolcanic intrusive rock of granitic composition

Harzburgite - a variety of peridotite; an ultramafic cumulate rock

Hornblendite - a mafic or ultramafic cumulate rock dominated by >90% hornblende

Hyaloclastite - a volcanic rock composed primarily of glasses and glassy tuff

Icelandite - a volcanic rock

Ignimbrite - a fragmental volcanic rock

Ijolite - a very rare silica-undersaturated plutonic rock 

Kimberlite - a rare ultramafic, ultrapotassic volcanic rock and a source of diamonds

Komatiite - an ancient ultramafic volcanic rock

Lamproite - an ultrapotassic volcanic rock

Lamprophyre - an ultramafic, ultrapotassic intrusive rock dominated by mafic phenocrysts in a feldspar groundmass

Latite - a silica undersaturated form of andesite

Lherzolite - an ultramafic rock, essentially a peridotite

Monzogranite - a silica undersaturated granite with <5% normative quartz

Monzonite - a plutonic rock with <5% normative quartz

Nepheline syenite - a silica undersaturated plutonic rock with nepheline replacing orthoclase

Nephelinite - a silica undersaturated plutonic rock with >90% nepheline

Norite - a hypersthene bearing gabbro

Obsidian - a type of volcanic glass

Pegmatite - an igneous rock (or metamorphic rock) with giant sized crystals

Peridotite - a plutonic or cumulate ultramafic rock composed of >90% olivine

Phonolite - a silica undersaturated volcanic rock; essentially similar to nepheline syenite

Picrite - an olivine-bearing basalt

Porphyry - a rock, usually granitic, with a porphyritic texture

Pumice - a fine grained, extremely vesicular volcanic rock

Pyroxenite - a coarse grained plutonic rock composed of >90% pyroxene

Quartz diorite - a diorite with >5% modal quartz

Quartz monzonite - an intermediate plutonic rock, essentially a monzonite with 5-10% modal quartz

Rhyodacite - a felsic volcanic rock which is intermediate between a rhyolite and a dacite

Rhyolite - a felsic volcanic rock

Comendite - a peralkaline rhyolite

Pantellerite - an alkaline rhyolite-rhyodacite with amphibole phenocrysts

Scoria - an extremely vesicular mafic volcanic rock

Sovite - a coarse grained carbonatite rock

Syenite - a plutonic rock dominated by orthoclase feldspar; a type of granitoid

Tachylyte - essentially a basaltic glass

Tephrite - a silica undersaturated volcanic rock; can be a generic term

Tonalite - a plagioclase-dominant granitoid

Trachyandesite - an alkaline intermediate volcanic rock

Benmoreite - sodic trachyandesite

Basaltic trachyandesite

Mugearite - sodic basaltic trachyandesite

Shoshonite - potassic basaltic trachyandesite

Trachyte - a silica undersaturated volcanic rock; essentially a feldspathoid-bearing rhyolite

Troctolite - a plutonic ultramafic rock containing olivine, pyroxene and plagioclase

Trondhjemite - a form of tonalite where plagioclase-group feldspar is oligoclase

Tuff - a fine grained volcanic rock formed from volcanic ash

Websterite - a type of pyroxenite, composed of clinoproxene and orthopyroxene

Wehrlite - an ultramafic plutonic or cumulate rock, a type of peridotite, composed of olivine and clinopyroxene

Argillite - a sedimentary rock composed primarily of clay-sized particles

Arkose - a sedimentary rock similar to sandstone

Banded iron formation - a fine grained chemical sedimentary rock composed of iron oxide minerals

Breccia - a sedimentary or tectonic rock composed of fragments of other, broken rocks

Cataclasite - a rock formed by faulting

Chalk - a sedimentary rock composed primarily of coccolith fossils

Chert - a fine grained chemical sedimentary rock composed of silica

Claystone - a sedimentary rock formed from clay

Coal - a sedimentary rock formed from organic matter

Conglomerate - a sedimentary rock composed of large rounded fragments of other rocks

Diamictite - a poorly sorted conglomerate

Coquina - a sedimentary carbonate rock formed by accumulation of abundant shell fossils and fragments

Diatomite - a sedimentary rock formed from diatom fossils

Dolomite or dolostone - a carbonate rock composed of the mineral dolomite +/- calcite

Evaporite - a chemical sedimentary rock formed by accumulation of minerals after evaporation

Flint - a form of chert

Greywacke - an immature sandstone with quartz, feldspar and rock fragments within a clay matrix

Gritstone - essentially a coarse sandstone formed from small pebbles

Itacolumite - porous, yellow sandstone

Jaspillite - an iron-rich chemical sedimentary rock similar to chert or banded iron formation

Laterite - a residual sedimentary rock formed from a parent rock under tropical conditions

Lignite - a sedimentary rock composed of organic material; otherwise known as Brown Coal

Limestone - a sedimentary rock composed primarily of carbonate minerals

Marl - a limestone with a considerable proportion of silicate material

Mudstone - a sedimentary rock composed of clay and muds

Oil shale - a sedimentary rock composed dominantly of organic material

Oolite - a chemical sedimentary limestone

Sandstone - a clastic sedimentary rock defined by its grain size

Shale - a clastic sedimentary rock defined by its grain size

Siltstone - a clastic sedimentary rock defined by its grain size

Travertine - a sedimentary rock containing calcite and iron oxides

Turbidite - a particular sequence of sedimentary rocks which form within the deep ocean environment

Wackestone - a matrix-supported carbonate sedimentary rock.

Anthracite - a type of coal

Amphibolite - a metamorphic rock composed primarily of amphibole

Blueschist - a metamorphic rock composed of sodic amphiboles with a distinct blue color

Eclogite - an ultra-high grade metamorphosed basalt or gabbro; also a facies of metamorphic rocks

Gneiss - a coarse grained metamorphic rock

Gossan - the product of the weathering of a sulfide rock or ore body

Granulite - a high grade metamorphic rock formed from basalt; also a facies of metamorphic rocks

Greenschist - a generic term for a mafic metamorphic rock dominated by green amphiboles

Greenstone

Hornfels - a metamorphic rock formed by heating by an igneous rock

Marble - a metamorphosed limestone

Migmatite - a high grade metamorphic rock verging upon melting into a magma

Mylonite - a metamorphic rock formed by shearing

Pelite - a metamorphic rock with a protolith of clay-rich (siltstone) sedimentary rock

Phyllite - a low grade metamorphic rock composed mostly of micaceous minerals

Psammite - a metamorphic rock with a protolith of quartz-rich (sandstone) sedimentary rock

Pseudotachylite - a glass formed by melting within a fault via friction

Quartzite - a metamorphosed sandstone typically composed of >95% quartz

Schist - a low to medium grade metamorphic rock

Serpentinite - a metamorphosed ultramafic rock dominated by serpentine minerals

Skarn - a metasomatic rock

Slate - a low grade metamorphic rock formed from shale or silts

Suevite - a rock formed by partial melting during a meteorite impact

Talc carbonate - a metamorphosed ultramafic rock with talc as an essential constituent; similar to a serpentinite

Soapstone - essentially a talc schist

Whiteschist - a high pressure metamorphic rock containing talc + kyanite

Rock classification. 

From what I remember of YR7 science, different types of rock are grouped into either:

Metamorphic / / Sedimentary / / Igneous.

Rocks are generally classified by mineral and chemical composition, by the texture of the constituent particles and by the processes that formed them. These indicators separate rocks into igneous, sedimentary, and metamorphic. They are further classified according to particle size. The transformation of one rock type to another is described by the geological model called the rock cycle.

Igneous rocks are formed when molten magma cools and are divided into two main categories: plutonic rock and volcanic. Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earth's crust (example granite), while volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta (examples pumice and basalt).^[1]

oxide bands

Sedimentary rocks are formed by deposition of either clastic sediments, organic matter, or chemical precipitates (evaporites), followed by compaction of the particulate matter and cementation during diagenesis. Sedimentary rocks form at or near the Earth's surface. Mud rocks comprise 65% (mudstone, shale and siltstone); sandstones 20 to 25% and carbonate rocks 10 to 15% (limestone and dolostone).^[1]

Metamorphic rocks are formed by subjecting any rock type (including previously formed metamorphic rock) to different temperature and pressure conditions than those in which the original rock was formed. These temperatures and pressures are always higher than those at the Earth's surface and must be sufficiently high so as to change the original minerals into other mineral types or else into other forms of the same minerals (e.g. by recrystallization).^[1]

The three classes of rocks—the igneous, the sedimentary and the metamorphic—are subdivided into many groups. There are, however, no hard and fast boundaries between allied rocks. By increase or decrease in the proportions of their constituent minerals they pass by every gradation into one another, the distinctive structures also of one kind of rock may often be traced gradually merging into those of another. Hence the definitions adopted in establishing rock nomenclature merely correspond to selected points (more or less arbitrary) in a continuously graduated series.

The use of rocks has had a huge impact on the cultural and technological development of the human race. Rocks have been used by humans and other hominids for more than 2 million years. Lithic technology marks some of the oldest and continuously used technologies. The mining of rocks for their metal ore content has been one of the most important factors of human advancement, which has progressed at different rates in different places in part because of the kind of metals available from the rocks of a region.

The prehistory and history of civilization is classified into the Stone Age, Bronze Age, and Iron Age. Although the Stone Age has ended virtually everywhere, rocks continue to be used to construct buildings and infrastructure. When so used, rocks are called dimension stone.