Rock Flashcards
Igneous, Plutonic; light color; pink/white; black minerals; high silica content
Granite
Igneous, Plutonic; medium color; black and white minerals; medium silica content
Diorite
Igneous, Plutonic; dark color, black and green minerals; Glistens; low silica content
Gabbro
Igneous, Plutonic; fragments of ash; air bubbles
Tuff / Pumice
Igneous, Volcanic; light color; pink/gray
Rhyolite
Igneous, Volcanic; medium color; some dark minerals; small sparkles/minerals
Andesite
Igneous, Volcanic; dark color; may have air holes; may have olivine; almost no crystals
Basalt
Igneous, Volcanic; volcanic glass; usually black; no mineral crystals; glass-like
Obsidian
Sedimentary, Chemical; rock salt; white or clear
Halite
Sedimentary, Chemical; white to gray; soft; tan layers; Fort Dodge
Gypsum
Sedimentary, Clastic; made of silt and clay; cannot see grains; soft and can break apart; thicker
Shale
Sedimentary, Clastic; made of sand; feels gritty; may have bedding layers
Sandstone
Sedimentary, Clastic; made of gravel +2mm; rounded fragments; pebble-like
Conglomerate
Sedimentary, Clastic; made of gravel +2mm; angular fragments; colored sections / “concrete”
Breccia
Sedimentary, Biochemical; fizzes in acid; white to tan; may have fossils
Limestone
Sedimentary, Biochemical; white and soft; can write with it
Chalk
Sedimentary, Biochemical; black and soft; stains fingers
Coal
Metamorphic, Foliated; very thin layers; no visible minerals
Slate
Metamorphic, Foliated; mica layers; may have garnet; has muscovite (sparkly white)
Schist
Metamorphic, Foliated; layers made of light and dark minerals; looks like striped granite; “tiger stripes”
Gneiss
Metamorphic, Non-foliated; parent=limestone; fizzes in acid; made of calcite; sparkly
Marble
Metamorphic, Non-foliated; parent=quartz sandstone; white / opaque
Quartzite
