Augite/Pyroxene

Dark green/black

Mineral

2 cleavage angles @ ~90 degrees

Apatite

Dull brown

Mineral

No cleavage

Similar to corundum

Does NOT scratch glass

Anthracite Coal

Black and Shiny

Metamorphic

Can be harder than bituminous

Non-foliated

Basalt

Extrusive

Igneous

Mafic black or grey

Biotite Mica

Black/Brown

Mineral

Flakes off in Sheets

1 planar cleavage

Calcite

Clear/yellow clear

Mineral

Effervesces in HCl

Corundum

Dull brown

Mineral

No cleavage

Scratches Glass

Diorite

Intermediate grey/dark grey

Igneous

Intrusive

Mostly plagioclase feldspar, biotite, hornblende, pyroxene

Medium grains maybe w/ porphyry

Hematite

Red-rust coloured

Mineral

Rubs off on hands (seriously...)

Fluorite

Translucent with green/purple glow inside

Mineral

Can't scratch glass

Gabbro

Dark green

Igneous

Dense

Intrusive/Coarse-grained

Galena

Silver

Mineral

Metallic

Cubic cleavage

Very dense

Garnet

Deep purple-red

Mineral

Gneiss

Pink and black or

White and black-banded

Metamorphic

Foliated

Granite

Do I really need to add a description?

Igneous

Graphite

Metallic, dull grey

Mineral

Poor cleavage

Writes on paper like lead

Gypsum

Cloudy-clear or opaque white

Mineral

Good cleavage

Soft; easily scratched with fingernail

Halite

Clear

Mineral

Cubic cleavage

Salty (if you care to taste it...?)

Does not effervesce with HCl

Hornblende

Black

Mineral

Kinda shiny

Splintery (devil-horn analogy)

Hornfels

Black

Metamorphic

Hard

Non-foliated

Magnetite

Rusty brown/black

Mineral

Extremely magnetic

Marble

Looks like the girls' bathroom stall

White/bluish

Metamorphic

Reacts with HCl

Non-foliated

Metaconglomerate

Often greenish

Metamorphic

Squished Pebbles

Non-foliated (do not confuse with Gneiss...because metaconglomerate is very mean.)

Hematite

Metallic silver/glittery

Mineral

Glitter rubs off

Magnetic

Muscovite Mica

Clear/gold

Mineral

Peals off in sheets

1-planar cleavage

Obsidian

volcanic glass

Dark in colour

Not crystalline

Olivine

Olive green colour

Mineral

Sometimes small green crystals

Pegmatitic Granite

More coarse than granite

Peridotite

Ultramafic

Igneous

Mostly pyroxene and olivine

Coarse-grained

Dense

Phyllite

Flat

Metamorphic

Like slate, but with reflective sheen

Foliated

Plagioclase Feldspar

Whitish grey

2 good cleavage planes at ~90 degrees

Porphyritic Andesite

Plagioclase + olivine/hornblende

Extrusive Igneous

Intermediate

Potassium Feldspar

Pinkish

2 planes of good cleavage at ~90 degrees

Pumice

Usually felsic/intermediate

Extrusive Igneous

Silky or fibrous

Can be vesicular

Pyrite

Fool's gold

(that's pretty much it, I guess?)

Quartz

Pink/clear in lab

Mineral

Scratches glass

Conchoidal fracture

Quartzite

Light-coloured like sandstone

Metamorphic

Smooth

Rhyolite

Felsic

Igneous extrusive

Usually quartz+plagioclase

Samples in lab usually smooth with small phenocrysts

Schist

Shimmery

Metamorphic

Looks like flakes

Foliated

Scoria

Dark

Igneous

Vesicular and rough

Looks and feels like dried sponge

Slate

Dark like mudstone

Hard

Flat and dull

Foliated

Talc

Pearly grey

Soapy texture

Volcanic Tuff

Volcanic Ash welded together

Arkose

Grey or reddish

Sedimentary

At least 25% feldspar

Quartz is commonly dominant

Fizzes slightly in HCl

Bituminous Coal

Usually black

Sedimentary

Dull or bright bands

Soft

Breccia

Broken mineral fragments cemented together

Grains bigger than tuff

Calcerinite (dune limestone)

Made up of shells and quartz sand cemented together

Chalk

White

Sedimentary

Soft and porous

Chert

Usually grey to brown

Sedimentary

Finegrained and microfibrous

Conglomerate

Sedimentary

Rounded rocks cemented together

Coquina

Mainly calcite

Think of hashbrowns

Hematitic Sandstone

Sedimentary

Composed of quartz and/or feldspar

Lignite

Brownish-black

Sedimentary

Will probably be in bag

Micrite

Grey to tan

Sedimentary

Dense and uniform

Fine-grained

Effervesces in HCl

Conchoidal fracture

Mudstone

Looks like hard clay/mud

Fine-grained sedimentary

Oolitic Limestone

Look for the 'O's!

Quartz Sandstone

Sedimentary rock of quartz sand particles

Rock Salt

Is salty (if you care to lick it...?)

coloured

Cubic

Basically giant salt