Rock Identifier

Category

Sedimentary (Volcanic)

Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.

Amygdaloidal Rhyolite (Amygdaloidal Rhyolite (Felsic volcanic rock)) — igneous

Amygdaloidal Rhyolite

Amygdaloidal Rhyolite (Felsic volcanic rock)

Pumice (Felsic Volcanic Glass / Vesicular Rhyolite) — Igneous

Pumice

Felsic Volcanic Glass / Vesicular Rhyolite

Obsidian (Volcanic Glass (Primary component: SiO2)) — igneous

Obsidian

Volcanic Glass (Primary component: SiO2)

Porphyritic Rhyolite (Red Porphyry) (Porphyritic Rhyolite (Felsic volcanic rock)) — igneous

Porphyritic Rhyolite (Red Porphyry)

Porphyritic Rhyolite (Felsic volcanic rock)

Porphyritic Rhyolite (Red Porp) (Porphyritic Rhyolite (Felsic volcanic rock)) — igneous

Porphyritic Rhyolite (Red Porp)

Porphyritic Rhyolite (Felsic volcanic rock)

Obsidian / Chert (Arrowhead Artifact) (Obsidian (volcanic glass, SiO2 with impurities)) — igneous

Obsidian / Chert (Arrowhead Artifact)

Obsidian (volcanic glass, SiO2 with impurities)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide)) — Igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide)

Obsidian (Apache Tear) (Amorphous Volcanic Glass (SiO2 + impurities)) — igneous

Obsidian (Apache Tear)

Amorphous Volcanic Glass (SiO2 + impurities)

Obsidian (Obsidian (Volcanic Glass, SiO2 + impurities)) — igneous

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Apache Tear (Hydrated Obsidian (Natural Volcanic Glass)) — igneous

Apache Tear

Hydrated Obsidian (Natural Volcanic Glass)

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

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Basalt with Scoria (Mafic Volcanic Rock (Basalt/Scoria)) — igneous

Basalt with Scoria

Mafic Volcanic Rock (Basalt/Scoria)

Apache Tear (Obsidian) (Volcanic glass (SiO2 - Silicon Dioxide)) — igneous

Apache Tear (Obsidian)

Volcanic glass (SiO2 - Silicon Dioxide)

Black Obsidian (Obsidian, volcanic glass (Amorphous SiO₂)) — Igneous Rock

Black Obsidian

Obsidian, volcanic glass (Amorphous SiO₂)

Basalt River Cobble (Basalt (Aphanitic Mafic Volcanic Rock)) — igneous

Basalt River Cobble

Basalt (Aphanitic Mafic Volcanic Rock)

Mahogany Obsidian (Volcanic Glass with Hematite/Magnetite inclusions) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Obsidian (Obsidian (Volcanic Glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Apache Tear (Obsidian) (Hydrated volcanic glass (SiO2 with inclusions)) — igneous

Apache Tear (Obsidian)

Hydrated volcanic glass (SiO2 with inclusions)

Basalt (Amygdaloidal) (Amygdaloidal Basalt) — igneous

Basalt (Amygdaloidal)

Amygdaloidal Basalt

Greenstone (Greenschist (metamorphosed mafic igneous rock)) — metamorphic

Greenstone

Greenschist (metamorphosed mafic igneous rock)

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

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (with Limonite staining) (Arenite (primarily SiO2 with FeO(OH)·nH2O)) — sedimentary

Sandstone (with Limonite staining)

Arenite (primarily SiO2 with FeO(OH)·nH2O)

Conglomerate (Polymictic Conglomerate) — sedimentary

Conglomerate

Polymictic Conglomerate

Limestone (specifically Bituminous or Carbonaceous Limestone) (Calcium Carbonate (CaCO3) with Organic Impurities) — sedimentary

Limestone (specifically Bituminous or Carbonaceous Limestone)

Calcium Carbonate (CaCO3) with Organic Impurities

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Limonite (Ironstone) (Hydrated Iron Oxide (FeO(OH)·nH2O)) — mineral

Limonite (Ironstone)

Hydrated Iron Oxide (FeO(OH)·nH2O)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic Extrusive volcanic rock)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive volcanic rock)

Basalt (Basalt (Aphanitic-to-porphyritic mafic volcanic rock)) — igneous

Basalt

Basalt (Aphanitic-to-porphyritic mafic volcanic rock)

Sardonyx Agate Sphere (Cryptocrystalline Quartz (SiO2) with iron oxide inclusions) — mineral

Sardonyx Agate Sphere

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Carnelian Agate (Silicon Dioxide (SiO2) with iron oxide inclusions) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide inclusions

Olivine (Peridot) (Magnesium Iron Silicate (Mg, Fe)2SiO4) — mineral

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Snowflake Obsidian (Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)) — Igneous

Snowflake Obsidian

Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)

Basalt (Basalt) — igneous

Basalt

Basalt

Basalt with Desert Varnish (Mafic Volcanic Rock (Fe/Mg rich Silicate)) — igneous

Basalt with Desert Varnish

Mafic Volcanic Rock (Fe/Mg rich Silicate)

Basalt (Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)) — igneous

Basalt

Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag) (Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)) — mineraloid / industrial byproduct

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)

Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)

mineraloid / industrial byproduct

Water and Silt (Sedimentary Environment) (Suspended Sediment / H2O (dihydrogen monoxide)) — sedimentary

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

Quartz-veined Sedimentary Rock (Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)) — sedimentary

Quartz-veined Sedimentary Rock

Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)

Chert (and associated Sedimentary rocks) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (and associated Sedimentary rocks)

Microcrystalline Silica (SiO2)

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)

Ironstone Concretion / Limonite (Goethite and Limonite (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion / Limonite

Goethite and Limonite (FeO(OH)·nH2O)