Basalt
Basaltic Mafic Rock
Category
Browse sedimentary and igneous specimens identified by the Rock Identifier community.
Basalt
Basaltic Mafic Rock
Granite (likely a river or beach pebble)
Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)
Magnetite (or Magnetic Iron Ore)
Magnetite (Fe3O4)
Chert / Flint Arrowheads
Cryptocrystalline Quartz (SiO2)
Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)
Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)
Sandstone
Arenite (SiO2 primarily)
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
Sedimentary Breccia
Clastic Breccia (CaCO3/SiO2 matrix)
Granite
Phaneritic Igneous Rock (Granite)
Basalt
Extrusive mafic igneous rock
Granite
Phaneritic Igneous Rock (Granite)
Chert (Jasper)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Orthoclase Feldspar (Granitic)
KAlSi3O8 (Potassium Feldspar)
Peridotite
Peridotite (Ultramafic Rock)
Dalmatian Stone
Dalmatian Jasper / Aplite
Labradorite (Larvikite variety)
(Na,Ca)(Al,Si)4O8 (Plagioclase Feldspar)
Granite
Granite (Phaneritic intrusive igneous rock)
Snowflake Obsidian
Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)
Granite
Granite
Sodalite
Sodalite: Na8(Al6Si6O24)Cl2
Greenstone (Epidosite/Altered Diorite)
Metabasalt or Meta-andesite / Epidotized Diorite
Granite (Pink/Potassium Feldspar rich)
Granite (K-feldspar rich intrusive igneous rock)
Basalt
Basalt
Pink Granite
Granite (Felsic Plutonic Rock)
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
Pink Granite
Phaneritic intrusive igneous rock (high Orthoclase Feldspar content)
Granite
Phaneritic Intrusive Igneous Rock (Granite)
Granite
Phaneritic Plutonic Felsic Rock (KAlSi3O8 + SiO2 + NaAlSi3O8)
Granite
Phaneritic Plutonic Felsic Rock (K-Feldspar + Quartz + Plagioclase)
Granite
Granite (composed of Quartz, Feldspar, and Mica)
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
Granite
Granite (compositionally: Quartz, Feldspar, Mica)
Gabbro
Gabbro (Mafic Plutonic Rock)
Quartz (in matrix)
Quartz (SiO₂)
Quartz-veined Sandstone
Quartzite-veined Arenite / SiO2 and quartz sand
Ironstone Concretion / Chert Nodules
Iron-rich Sedimentary Concretion (Fe2O3 / SiO2 mix)
Ironstone (Limonite/Hematite concretion)
Ferruginous Siltstone / Goethite (FeO(OH))
Shale
Fissile mudrock (composed of clay-sized particles and detrital grains)
Sandstone
Arenite (primarily SiO2)