Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Category
Browse mixed (predominantly sedimentary and igneous) specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Vesicular Basalt (Scoria)
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Aquamarine and clear quartz
Aquamarine (Be3Al2Si6O18), Quartz (SiO2)
Banded Gneiss
Gneiss (pronounced "nice")
Granite Pebble
Granite (a phaneritic intrusive igneous rock consisting of quartz, alkali feldspar, and plagioclase)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-feldspar, Quartz, and Biotite)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)
Granite
Phaneritic intrusive igneous rock (composition: Quartz, Alkali Feldspar, Plagioclase Feldspar)
Pink Granite
Felsic Intrusive Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)
Granodiorite
Granodiorite (Phaneritic intrusive igneous rock containing Plagioclase, Quartz, and Biotite/Amphibole)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Plagioclase)
Granite
Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O
Granite
Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)
Sandstone
Arenite (composed mainly of SiO2)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
Reddish Brown Claystone or Siltstone
Argillite / Siltstone / Claystone
Dendritic Agate or Manganese Nodule in Chert/Limestone
Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions
Red Jasper (River Stone)
Jasper (Silicon Dioxide, SiO2 plus iron oxide inclusions)
Sandstone (Micaceous)
Arenite (primarily SiO2 with Phyllosilicates)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Sandstone (Red)
Arenite (Fe2O3 heavy)
Sandstone
Arenite (SiO2 based)
Sandstone (Painted)
Arenite (primarily SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone Concretion
Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Piddock bored rock (likely Mudstone or Shale)
Ichnofossil (Gastrochaenolites borings) in Fine-grained Sedimentary Rock
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss (likely)
Gneiss
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
Greenstone
Greenschist (metamorphosed mafic igneous rock)
Olivine (Peridotite)
(Mg, Fe)2SiO4 (Magnesium Iron Silicate)
Granite or Granodiorite (Weathered)
Granite
Red Granite
Potassium-feldspar rich Granite
Granite
Granite
Granodiorite
Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Granodiorite
Granodiorite