Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Quartzite (River Cobble) (SiO2 (Quartz-rich Metamorphic Rock)) — metamorphic

Quartzite (River Cobble)

SiO2 (Quartz-rich Metamorphic Rock)

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal) (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Quartz Crystal Cluster (Silicon Dioxide (SiO2)) — mineral

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Muscovite Schist (Mica Schist (KAl2(AlSi3O10)(OH)2)) — metamorphic

Muscovite Schist

Mica Schist (KAl2(AlSi3O10)(OH)2)

Sandstone (Banded) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Granite (Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)) — igneous

Granite

Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)

Eudialyte in Matrix (Na15Ca6Fe3Zr3Si26O72(OH,Cl,H2O)3) — mineral

Eudialyte in Matrix

Na15Ca6Fe3Zr3Si26O72(OH,Cl,H2O)3

Limonite (Iron Ore) (FeO(OH)·nH2O (Hydrous ferric oxide)) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Basalt (Extrusive Mafic Igneous Rock) — igneous

Basalt

Extrusive Mafic Igneous Rock

Basalt (Basalt) — igneous

Basalt

Basalt

Pink Granite (Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)

Tree Agate (Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony) — sedimentary

Tree Agate

Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony

Chert (Jasper/Chalcedony variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Devil's Toenail (Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)) — sedimentary

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Coquina Jasper (Fossiliferous Chalcedony (SiO2)) — sedimentary

Coquina Jasper

Fossiliferous Chalcedony (SiO2)

Garnet in Matrix (Eclogite) (Eclogite, featuring Almandine or Pyrope Garnet [X3Y2(SiO4)3]) — metamorphic

Garnet in Matrix (Eclogite)

Eclogite, featuring Almandine or Pyrope Garnet [X3Y2(SiO4)3]

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Quartz Druze (Silicon Dioxide (SiO2)) — mineral

Quartz Druze

Silicon Dioxide (SiO2)

Coquina (Biogenic Limestone (CaCO3)) — sedimentary

Coquina

Biogenic Limestone (CaCO3)

Basalt Column Section (Columnar Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt Column Section

Columnar Basalt (Mafic Extrusive Igneous Rock)

Sandstone (Quartzose) (Arenite (SiO2 based)) — sedimentary

Sandstone (Quartzose)

Arenite (SiO2 based)

Limonite (Iron Ore) (FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)

Ferruginous Sandstone (with possible Epidote/Chlorite coloring) (Sandstone (SiO2 dominated with Fe2O3 staining)) — sedimentary

Ferruginous Sandstone (with possible Epidote/Chlorite coloring)

Sandstone (SiO2 dominated with Fe2O3 staining)

Agate (specifically Carnelian Agate or Lake Superior style Agate) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Agate (specifically Carnelian Agate or Lake Superior style Agate)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Unakite (Unakite (Metasomatized Granite)) — metamorphic

Unakite

Unakite (Metasomatized Granite)

Serpentinite (River Pebble) (Serpentinite (complex of Antigorite, Lizardite, and Chrysotile: Mg3Si2O5(OH)4)) — metamorphic

Serpentinite (River Pebble)

Serpentinite (complex of Antigorite, Lizardite, and Chrysotile: Mg3Si2O5(OH)4)

Granodiorite (Granodiorite (calc-alkaline phaneritic igneous rock)) — igneous

Granodiorite

Granodiorite (calc-alkaline phaneritic igneous rock)

Granite (Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)) — igneous

Granite

Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)

Pumice (Pumice (Vesicular Rhyolite/Andesite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Basalt (Water-worn pebble) (Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)) — igneous

Basalt (Water-worn pebble)

Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)

Banded Siltstone or Argillite (Siltstone (primarily SiO2 with Al and Fe oxides)) — sedimentary

Banded Siltstone or Argillite

Siltstone (primarily SiO2 with Al and Fe oxides)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Granite (Phaneritic Acidic Igneous Rock (Granite Group)) — igneous

Granite

Phaneritic Acidic Igneous Rock (Granite Group)

Granite (Phaneritic Felsic Intrusive Rock) — igneous

Granite

Phaneritic Felsic Intrusive Rock

Sandstone (with potential Arkose/Lithic characteristics) (Arenite (Sedimentary rock composed of sand-sized grains)) — sedimentary

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartzite (Metamorphic Quartz (SiO2)) — metamorphic

Quartzite

Metamorphic Quartz (SiO2)

Pumice (Volcanic Rock) (Vesicular volcanic rock (composed largely of amorphous volcanic glass)) — igneous

Pumice (Volcanic Rock)

Vesicular volcanic rock (composed largely of amorphous volcanic glass)

Desert Rose (Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O) — mineral

Desert Rose

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O