Rock Identifier

Category

Mineral, Specifically A Rock Fragment

Browse mineral, specifically a rock fragment specimens identified by the Rock Identifier community.

River/Stream Pebble (Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)) — Mineral, specifically a rock fragment

River/Stream Pebble

Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)

Mineral, specifically a rock fragment

Pebble (Clast (specifically a granule or small pebble)) — Sedimentary

Pebble

Clast (specifically a granule or small pebble)

Chalcedony (Agate/Chert) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Chert)

Silicon Dioxide (SiO2)

Chert (specifically a fragment with Desert Varnish) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically a fragment with Desert Varnish)

Microcrystalline quartz (SiO2)

Sandstone (Graywacke) (Clastic Sedimentary Rock (Lithic Sandstone)) — sedimentary

Sandstone (Graywacke)

Clastic Sedimentary Rock (Lithic Sandstone)

Sandstone (likely Greywacke or Siltstone variety) (Arenite / Siltstone (primarily SiO2)) — sedimentary

Sandstone (likely Greywacke or Siltstone variety)

Arenite / Siltstone (primarily SiO2)

Sandstone (with ripple marks) (Arenite / Quartz Sandstone) — sedimentary

Sandstone (with ripple marks)

Arenite / Quartz Sandstone

Ferruginous Sandstone (Sandstone (rich in iron oxides/hydroxides)) — sedimentary

Ferruginous Sandstone

Sandstone (rich in iron oxides/hydroxides)

Sandstone (Ferruginous) (Arenite (with iron oxide cement, Fe2O3)) — sedimentary

Sandstone (Ferruginous)

Arenite (with iron oxide cement, Fe2O3)

Sandstone (with garnet granules) (Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)) — sedimentary

Sandstone (with garnet granules)

Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)

Sandstone (lithic/greywacke variety) (Arenite (composed primarily of SiO2 with various lithic fragments)) — sedimentary

Sandstone (lithic/greywacke variety)

Arenite (composed primarily of SiO2 with various lithic fragments)

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone (specifically Banded Sandstone) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (specifically Banded Sandstone)

Clastic sedimentary rock (primarily SiO2)

Quartz Geode / Druzy Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Chert (specifically Pink/Tan Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Pink/Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Sandstone (Hematitic) (Clastic sedimentary rock (SiO2 with Fe2O3 inclusions)) — sedimentary

Red Sandstone (Hematitic)

Clastic sedimentary rock (SiO2 with Fe2O3 inclusions)

Chert (Arrowhead Fragment) (Chert / Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Arrowhead Fragment)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Limestone (specifically a Crushed Aggregate fragment) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (specifically a Crushed Aggregate fragment)

Calcium Carbonate (CaCO3)

Unidentifiable Rock Fragment — Uncertain

Unidentifiable Rock Fragment

Sandstone (specifically an Iron-Concretion) (Arenite with Iron Oxide (Limonite/Goethite) cementation) — sedimentary

Sandstone (specifically an Iron-Concretion)

Arenite with Iron Oxide (Limonite/Goethite) cementation

Quartz (specifically Milky or Clear Quartz fragment) (Silicon Dioxide (SiO2)) — mineral

Quartz (specifically Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Granite Pebble (Granite (composed primarily of Quartz, Feldspar, and Mica)) — igneous

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica)

Pebble (river rock/beach pebble) (Pebble (clast size class)) — Sedimentary Rock

Pebble (river rock/beach pebble)

Pebble (clast size class)

Sedimentary Rock

Sandstone (Ferruginous) (Arenite (Fe-rich)) — sedimentary

Sandstone (Ferruginous)

Arenite (Fe-rich)

Mammoth Tooth Fragment (Mammuthus primigenius (fossilized dentin and enamel)) — sedimentary

Mammoth Tooth Fragment

Mammuthus primigenius (fossilized dentin and enamel)

Chalcedony (Agate/Quartz) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Quartz)

Silicon Dioxide (SiO2)

Sandstone (specifically Picture Sandstone or Wonderstone) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (specifically Picture Sandstone or Wonderstone)

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous) (Arenite with Iron Oxide cement (SiO2 + Fe2O3)) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

Sandstone (specifically Flagstone) (Arenite (primarily composed of SiO2)) — sedimentary

Sandstone (specifically Flagstone)

Arenite (primarily composed of SiO2)

Quartz / Common Opal Transition (Silicon Dioxide (SiO2)) — mineral

Quartz / Common Opal Transition

Silicon Dioxide (SiO2)

Sandstone Beach Pebble (Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)) — sedimentary

Sandstone Beach Pebble

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)

Sandstone (Ferruginous) (Arenite with Iron Oxide (Limonite/Hematite) coating) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxide (Limonite/Hematite) coating

Sandstone (Micaceous/Feldspathic variant) (Arenite (specifically subarkose or lithic arenite)) — sedimentary

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Jasper Breccia (Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)) — sedimentary

Jasper Breccia

Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Quartz Druze on Matrix (Geode Fragment) (Quartz (Silicon Dioxide, SiO2)) — mineral

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Coarse Sand Grain / Lithic Fragment (Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)) — sedimentary

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Oolitic Chert (Silicon Dioxide (SiO2) with Oolitic texture) — sedimentary

Oolitic Chert

Silicon Dioxide (SiO2) with Oolitic texture

Concrete Fragment (Hardened Portland Cement Composite) — Anthropogenic (Man-made material mimicking sedimentary rock)

Concrete Fragment

Hardened Portland Cement Composite

Anthropogenic (Man-made material mimicking sedimentary rock)

Basalt with Magnetite (Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)) — igneous

Basalt with Magnetite

Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)

Sandstone (specifically Lithic or Quartz Arenite) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (specifically Lithic or Quartz Arenite)

Arenite (composed primarily of SiO2)

Rough Quartz in Pegmatite Matrix (Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite) — igneous

Rough Quartz in Pegmatite Matrix

Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite