Rock Identification

Earth History Lab Midterm

Igneous, olive green to black, mostly crystals

Gabbro

Igneous, mostly crystals, mix of light and dark

Diorite

Igneous, mostly crystals, light in color a little dark minerals

Granite

Igneous, Olive green to black, Mafic

Basalt

Igneous, Mostly not crystals, Gray-green, Intermidiate

Andesite

Igneous, Mostly not crystals, Felsic

Rhyolite

Metamorphic, distinct bands, visible crystals

Gniess

Metamorphic, not layers mostly crystal reacts to HCl and doesn’t scratch glass

Marble

Metamorphic, Visible layers not crystals

Schist

Metamorphic, platy layers no minerals or crystals visible

Slate

Metamorphic, mostly crystals, scratches glass and no reaction to HCl

quartzite

Sedimentary, high density and red streak, not made up of other rocks

Iron ore

Sedimentary, not made up of other rocks, waxy feel, conchoidal fracture, no visible crystals

Chert

Sedimentary, not made of other rocks, looks like crystals, scratched by fingernail

Gyprock

Sedimentary, not made of other rocks, looks like crystals, taste salty

Rocksalt

Sedimentary, made up of other rocks large rounded grains

Conglomerate

Sedimentary, made up of other rocks large angular grains

Breccia

Sedimentary, made up of other rocks, sand sized grains easily visible

Sandstone

Sedimentary, made up of other rocks, not visible grains, gritty feel

Siltstone

Sedimentary, made up of other rocks, grains not visible, smooth feel

Shale

Sedimentary, not made up of other rocks dark black easy streak, low density

Coal

Sedimentary, not made up of other rocks, small reaction to HCl

Dolostone

Sedimentary, not made up of other rocks, reacts to HCl, no visible grains or fossils

Micrite

Sedimentary, not made up of other rocks, reacts to HCl, oolitic

Ooidal Limestone

Sedimentary, not made up of other rock, reacts to HCl, has fossils like leach shaped lumps

Fossiliferous Limestone