Rock Identifier

Category

Igneous Or Sedimentary (Water Worn)

Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.

Shale (Fissile mudrock (composed of clay-sized particles and detrital grains)) — sedimentary

Shale

Fissile mudrock (composed of clay-sized particles and detrital grains)

Pumice (Pumice (volcanic glass foam)) — igneous

Pumice

Pumice (volcanic glass foam)

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony) (Chert (microcrystalline quartz)) — Metamorphic Rock

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Metamorphic Rock

Amazonite (Microcline (KAlSi3O8 with lead impurities)) — mineral

Amazonite

Microcline (KAlSi3O8 with lead impurities)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst (Silicon Dioxide (SiO2) with trace Iron (Fe3+)) — mineral

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe3+)

Amazonite (K(AlSi3O8) - Microcline) — mineral

Amazonite

K(AlSi3O8) - Microcline

Amazonite (Potassium Feldspar (KAlSi3O8) with lead impurities) — mineral

Amazonite

Potassium Feldspar (KAlSi3O8) with lead impurities

River Pebble (Basalt or Gabbro) (Mafic Igneous Rock) — igneous

River Pebble (Basalt or Gabbro)

Mafic Igneous Rock

Amazonite (KAlSi3O8 (Potassium Aluminum Silicate)) — mineral

Amazonite

KAlSi3O8 (Potassium Aluminum Silicate)

Black Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Black Opal

Hydrated Silica (SiO2·nH2O)

Pumice (Pumice (Vitreous volcanic rock)) — igneous

Pumice

Pumice (Vitreous volcanic rock)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Tufa (Calcareous Tufa (CaCO3)) — sedimentary

Tufa

Calcareous Tufa (CaCO3)

Sandstone (Yellow/Siltstone variant) (Arenite (SiO2 primarily)) — sedimentary

Sandstone (Yellow/Siltstone variant)

Arenite (SiO2 primarily)

Sandstone (Arenite (predominantly SiO2)) — sedimentary

Sandstone

Arenite (predominantly SiO2)

Sandstone (Arenite (SiO2 based with mineral cement)) — sedimentary

Sandstone

Arenite (SiO2 based with mineral cement)

Sandstone (Quartzite-rich River Cobble) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (Quartzite-rich River Cobble)

Clastic sedimentary rock (primarily SiO2)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

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

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Ferruginous) (Arenite (with Hematite/Limonite cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (with Hematite/Limonite cement)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (Ferruginous) (Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)) — sedimentary

Sandstone (Ferruginous)

Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)

Conglomerate (Polymictic Conglomerate) — sedimentary

Conglomerate

Polymictic Conglomerate

Granite (Phaneritic plutonic rock (SiO2 range 65-75%)) — igneous

Granite

Phaneritic plutonic rock (SiO2 range 65-75%)

Crushed Limestone (Sedimentary Carbonate Rock (CaCO3)) — sedimentary

Crushed Limestone

Sedimentary Carbonate Rock (CaCO3)

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

Sandstone (with ripple marks)

Arenite / Quartz Sandstone

Basalt (River Rock/Cobble) (Basalt (no specific mineral formula as it's a rock)) — Igneous

Basalt (River Rock/Cobble)

Basalt (no specific mineral formula as it's a rock)

Pumice (Pumicite (Volcanic glass with vesicular texture)) — igneous

Pumice

Pumicite (Volcanic glass with vesicular texture)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Pumice (Pumiceous rhyolite) — igneous

Pumice

Pumiceous rhyolite

Pumice (Pumice (a highly vesicular volcanic rock)) — igneous

Pumice

Pumice (a highly vesicular volcanic rock)

Dendritic Agate (also known as Dendritic Siltstone or Mudstone) (Silicon Dioxide with Manganese/Iron Oxide inclusions (SiO2 + MnO2)) — sedimentary

Dendritic Agate (also known as Dendritic Siltstone or Mudstone)

Silicon Dioxide with Manganese/Iron Oxide inclusions (SiO2 + MnO2)

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

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Pumice (Pumice (Amorphous volcanic glass)) — igneous

Pumice

Pumice (Amorphous volcanic glass)

Quartz Geode (Silicon Dioxide (SiO2) in a Geode body) — sedimentary or igneous (host environment)

Quartz Geode

Silicon Dioxide (SiO2) in a Geode body

sedimentary or igneous (host environment)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Garnet (Pyrope-Almandine series) (Garnet Group, (Mg,Fe)3Al2Si3O12) — mineral

Garnet (Pyrope-Almandine series)

Garnet Group, (Mg,Fe)3Al2Si3O12

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

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Scoria (Lava Rock) (Vesicular Basalt / Scoria) — igneous

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Banded Calcite (often commercially sold as Mexican Onyx or Green Onyx) (Calcium Carbonate (CaCO3)) — sedimentary

Banded Calcite (often commercially sold as Mexican Onyx or Green Onyx)

Calcium Carbonate (CaCO3)

Sandstone (with Iron Staining) (Clastic sedimentary rock (primarily Quartz - SiO2)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz - SiO2)