Rock Identifier

Category

Mineral, Often A Rock Given Its Aggregate Nature

Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.

Ferruginous Sandstone (Ironstone) (Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)) — sedimentary

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Pebble or Cobble (likely composed of sandstone or conglomerate) (Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)) — Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)

Pebble or Cobble (likely composed of sandstone or conglomerate)

Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)

Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)

Chert (Nodule) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Granite Gneiss (High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)) — metamorphic

Granite Gneiss

High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)

Banded Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Banded Agate

Cryptocrystalline Quartz (SiO2)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Jasper (Silicon dioxide (SiO2) with impurities) — sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Basalt River Pebble (Mafic volcanic rock (Basalt)) — igneous

Basalt River Pebble

Mafic volcanic rock (Basalt)

Chert (specifically Flint or Dark Chalcedony) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Flint or Dark Chalcedony)

Silicon Dioxide (SiO2)

Conglomerate (Conglomerate (Sedimentary Clastic Rock)) — sedimentary

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Basalt with Quartz Veins (Amygdaloidal Basalt (matrix) with Crystalline SiO2 (veins)) — igneous

Basalt with Quartz Veins

Amygdaloidal Basalt (matrix) with Crystalline SiO2 (veins)

Basalt with Weathered Surface (Basalt) — Igneous

Basalt with Weathered Surface

Basalt

Chert (Flint Nodular Variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint Nodular Variety)

Microcrystalline Quartz (SiO2)

Quartz (Milky or Smoky variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Smoky variety)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz / Quartzite) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Sandstone (Ferruginous) (Arenite (composed primarily of SiO2 with Fe2O3 cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Banded Gneiss (Gneiss (high-grade metamorphic silicate rock)) — metamorphic

Banded Gneiss

Gneiss (high-grade metamorphic silicate rock)

Limonite Concretion (Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O) — sedimentary

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Hypersthene (Hypersthene ((Mg,Fe)SiO₃)) — Mineral

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

Mica Schist (Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)) — metamorphic

Mica Schist

Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)

Fossiliferous Limestone (Coquina / Shell Limestone) (Bioclastic Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone (Coquina / Shell Limestone)

Bioclastic Limestone (CaCO3)

Conglomerate (Clastic sedimentary rock (Polymictic Conglomerate)) — sedimentary

Conglomerate

Clastic sedimentary rock (Polymictic Conglomerate)

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Crushed Limestone (Calcite-rich Sedimentary Rock (CaCO3)) — sedimentary

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Greywacke (River Slikkenstone) (Greywacke (Impure Sandstone)) — sedimentary

Greywacke (River Slikkenstone)

Greywacke (Impure Sandstone)

Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

River Cobble (Quartzite) (Meta-orthoquartzite) — metamorphic

River Cobble (Quartzite)

Meta-orthoquartzite

Carnelian (Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

River Pebble (Greywacke or Quartzite-rich Sandstone) (Lithic Sandstone (primarily SiO2 with rock fragments)) — sedimentary

River Pebble (Greywacke or Quartzite-rich Sandstone)

Lithic Sandstone (primarily SiO2 with rock fragments)

Sandstone (likely Siltstone or fine-grained Sandstone) (Sedimentary Rock (Clastic)) — sedimentary

Sandstone (likely Siltstone or fine-grained Sandstone)

Sedimentary Rock (Clastic)

Ocherous Sandstone (Ferruginous Sandstone) (Ferruginous Arenite (SiO2 with Fe2O3)) — sedimentary

Ocherous Sandstone (Ferruginous Sandstone)

Ferruginous Arenite (SiO2 with Fe2O3)

Granite (Granite) — igneous

Granite

Granite

Quartz Pebble (Water-worn Quartzite) (Silicon Dioxide (SiO2)) — metamorphic

Quartz Pebble (Water-worn Quartzite)

Silicon Dioxide (SiO2)

Druzy Quartz on Host Rock (Silicon Dioxide (SiO2)) — mineral

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2)

Pumice (Vesicular Rhyolite or Dacite Pumice (Amorphous volcanic glass)) — igneous

Pumice

Vesicular Rhyolite or Dacite Pumice (Amorphous volcanic glass)

Basalt (River Stone) (Basalt) — igneous

Basalt (River Stone)

Basalt

Orca Agate (Blue Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Orca Agate (Blue Chalcedony)

Silicon Dioxide (SiO2)

Porphyry (Porphyritic Basalt or Porphyritic Andesite) — igneous

Porphyry

Porphyritic Basalt or Porphyritic Andesite

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Chalcedony (Agate/Chert) (Microcrystalline Quartz (SiO2)) — sedimentary

Chalcedony (Agate/Chert)

Microcrystalline Quartz (SiO2)

Red Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2)