Obsidian

Extrusive Igneous Rock

Texture: Glassy

Color: Intermediate between light (felsic) and dark

         (mafic) (blackish/brownish in color)

Dunite

Intrusive Igneous Rock

Texture: Phaneric

Minerals: Olivine with mica crystals intermittent 

Color: Ultramafice (green crystalline)

Pumice

Extrusive Igneous Rock

Texture: Vesicular

Minerals: Felsic 

Color: Felsic (white with a few grayish flecks)

Rhyolite

Extrusive Igneous Rock

Texture: Aphanitic

Minerals: Felsic

Color: Felsic (grayish with a few dark crystals)

Basalt

Extrusive Igneous Rock

Texture: Aphanitic

Minerals: unknown

Color: Mafic (no grains visible, very dark/black)

Scoria

Extrusive Igneous Rock

Texture: Vesicular

Minerals: unknown

Color: Mafic (black with 'rust', red/brown oxidation)

Granite

Intrusive Igneous Rock

Texture: Phaneric

Minerals: Felsic

Color: Felsic (orange and white crystals)

Remember: Granite - Granodiorite - Diorite

                  Light   -  light/dark    - dark w/some light

Tuff

Extrusive Igneous Rock

Texture: Fragmental

Minerals: Felsic

Color: Felsic (buff colored with flecks of brown lightly

         sprinkled in)

Andesite Porphyry

Intrusive Igneous Rock

Texture: Porphoritic

Minerals: unknown

Color: Intermediate between Felsic and Mafic (black

         andesitic groundmass; medium sized columnar

           black glass like crystals)

Gabbro

Intrusive Igneous Rock

Texture: Phaneric

Minerals: unknown

Color: Mafic (dark with white crystals - less than 50%)

Granodiorite

Intrusive Igneous Rock

Texture: Phaneric

Minerals: Felsic

Color: Felsic (fewer dark than light crystals)

Remember: Granite - Granodiorite - Diorite

                  Light   -   light/dark   -  dark w/some light

Diorite

Intrusive Igneous Rock

Texture: Phaneric

Minerals: unknown

Color: Intermediate between Felsic and Mafic (more

         dark than light crystals)

Remember: Granite - Granodiorite - Diorite

                  Light   -  light/dark    - dark w/some light