Rocks!

Chert

• Sedimentary

• Formed from radiolaria shells

• Main mineral is quartz

• Chemical

• Chert can often be bioclastic

Pink Granite

• Igneous

• Formed below the surface

• Felsic

• Main minerals are Potassium Feldspar, Quartz

• Also contains plagioclase feldspar, biotite, amphibole

• Phaneritic

Gabbro

• Igneous intrusive

• Forms below surface

• Contains plagioclase feldspar, pyroxene, a little olivine

• Phaneritic

• Mafic

Basalt

• Igneous

• Aphanitic

• Forms above surface

• Minerals: Plagioclase feldspar, pyroxene, olivine

• mafic

Amygdaloidal Basalt

• Apanitic

• Igneous

• Forms above surface

• Crystals (mostly quartz) grow in vesicles after rock is formed

• Mafic

Andesite

• Igneous

• Aphanitic

• Intermediate

• Forms below surface

• Minerals: Plagioclase, pyroxene, amphibole

Granodiorite

• Igneous

• Phaneritic

• Formed below the surface

• Minerals: Potassium feldspar, quartz, plagioclase, biotite, amphibole

• Intermediate

Granite Porphyry

• Porphyritic

• Felsic

• Formed by two different rates of cooling (eg. started cooling below the surface then rose and finished cooling above the surface)

• Minerals: potassium feldspar, quartz, plagioclase, amphibole, biotite

• Large minerals are called phenocrysts and small minerals are called ground-mass/matrix

White Granite

• Igneous

• Formed below the surface

• Phaneritic

• You can see the quartz cleavage planes

• Minerals: quartz, plagioclase, amphibole, biotite

• felsic

Rhyolite

• Igneous

• Aphanitic

• Felsic

• Formed above surface

• Minerals: potassium feldspar, quartz, plagioclase

Syenite

• Igneous

• Phaneritic

• Formed below surface

• Felsic

• Minerals: Potassium feldspar, plagioclase, biotite, amphibole

Pumice

• Igneous

• Felsic

• Vesicular

• Formed from magma cooling so quickly that gas cannot escape and forms air bubbles within the rock

Quartz Sandstone

• Sedimentary

• Clastic

• Sand sized particles

• Well-sorted

• Made up mostly of quartz

• Medium velocity transport (eg. slow stream or at a shore)

Shale

• Type of mudstone

• Mainly made of the mineral clay

• Clay sized particles

• Clastic

• Low velocity transport (eg. calm lake)

Conglomerate

• Sedimentary

• Clastic

• High Velocity transport (eg. fast stream or river)

• Pebble/boulder sized particles

Fossiliferous Limestone

• Sedimentary

• Chemical: bioclastic

• Contains fossils from ocean shells

• Mainly composed of calcite

• soft

Rock Salt

• Sedimentary

• Chemical

• Composed of soft mineral halite

Potash

• Sedimentary

• Chemical

• Mainly composed of mineral sylvite (KCl)

• Soft

Gypsum

• Sedimentary

• Chemical

• Very soft, when you scratch it it makes white dust

Slate

• Metamorphic

• Has slaty foliations

• Formed from shale

• Formed from regional metamorphism, intense pressure and heat

• Parallel cleavage

Quartz-Garnet-Muscovite Schist

• Metamorphic

• Schistose Foliation

• Formed by regional metamorphism (intense pressure and heat)

• Slate morphs into this

Garnet-Chlorite-Biotite Schist

• Metamorphic

• Schistose foliations

• High temp and pressure

• Regional metamorphism

• Formed from slate

Biotite Schist

• Metamorphic

• Schistose foliations

• Regional metamorphism

• Formed from slate

Quartzo-feldspathic Gneiss

• Metamorphic

• Gneissic foliations

• Regional metamorphism

• Main minerals: potassium feldspar, quartz

Marble

• Metamorphic

• Regional metamorphism

• Formed from Limestone

• Main mineral is calcite

• soft

Granite Gneiss

• Metamorphic

• Regional metamorphism

• Gneissic foliations

• Main minerals: quartz, potassium feldspar, quartz

Chlorite Schist

• Metamorphic

• Schistose foliations

• Regional metamorphism

• Looks like chlorite but it is a rock not a mineral

• Main mineral is chlorite

Amphibolite Gneiss

• Metamorphic

• Gneissic foliations

• Regional metamorphism

• Contains amphibole and garnet

Greywacke

• Sedimentary

• Clastic

• Sand sized particles

• Poorly sorted

• Medium velocity energy source (slow stream or a shore)

• Composed of quartz, k-feldspar, and clay

Calcite

• Mineral

• Rhombohedral cleavage

• Soft

• CaCO3

• Fizzes when HCl is put on it

• Non-silicate

• Carbonate

• Vitreous to dull

Chlorite

• Mineral

• Soft

• Dark green colour

• 1 perfect basal cleavage

• Silicate

• Hydrous Mg-Fe-Al silicate

• Pearly vitreous

Potassium Feldspar

• Mineral

• Hard

• Two directions of 90o cleavage

• Silicate

• KAlSi3O8

• Vitreous

Plagioclase Feldspar

• Mineral

• Silicate

• NaAlSi3O8- sodium rich, lighter colour

• CaAl2Si2O8- calcium rich, darker colour

• 2 close to 90o

• Vitreous

• Hard

• striations

Amphibole

• Mineral

• Silicate

• Hard

• Cleavage at 56o and 124o

• Dark colour

• Hydrous Na-Ca-Fe-Mg-Al silicate

• Vitreous dull

Pyroxene

• Mineral

• Hard

• Two directions of cleavage at 90o

• Dark green to black colour

• Vitreous to dull

• Silicate

• Ca-Fe-Mg-Na-Al silicate

Olivine

• Rough (sugary) texture

• Mineral

• Silicate

• Hard

• Olive colour

• No cleavage

• Vitreous

• (Mg,Fe)SiO4

Garnet

• Mineral

• Hard

• No cleavage

• 12 sided crystals (generally reddish)

• Vitreous

• Fe-Mg-Ca-Mn-Al silicate

• silicate

Quartz

• Mineral

• Hard

• No cleavage

• SiO2

• Silicate

• vitreous

Magnetite

• Mineral

• Magnetic

• Metallic black lustre

• Non-silicate

• Fe3O4

• No cleavage

Pyrite

• Mineral

• Hard

• Metallic Yellow lustre

• Shiny

• Non-silicate

• Sulfide

• FeS2

• Poor cleavage

Galena

• Mineral

• Soft

• Very dense, heavy

• Metallic grey lustre

• Parallel cleavage to cube faces

• Non-Silicate Sulfide

• PbS

Chalcopyrite

• Soft

• Mineral

• Metallic brassy yellow lustre

• Non-Silicate Sulfide

• CuFeS2

• Poor cleavage

Biotite Mica

• Mineral

• Soft

• Basal cleavage

• Dark colour

• Pearly

• Silicate

• Hydrous K-Al-Mg-Fe silicate

Muscovite Mica

• Mineral

• Soft

• Basal Cleavage

• Lighter Colour

• Pearly

• Silicate

• Hydrous K-Al silicate

Now you know your ROCKS!!