Rock Identifier

Category

Sedimentary (Volcanic)

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

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

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

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Black Obsidian (Volcanic Glass (Amorphous Silicon Dioxide, SiO2)) — igneous

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide, SiO2)

Basalt with Quartz/Quartzite Veins (Aphanitic Mafic Volcanic Rock with Siliceous Infillings) — igneous

Basalt with Quartz/Quartzite Veins

Aphanitic Mafic Volcanic Rock with Siliceous Infillings

Obsidian (Volcanic Glass (SiO2, usually 70% or more)) — igneous

Obsidian

Volcanic Glass (SiO2, usually 70% or more)

Porphyritic Basalt (Porphyritic Fine-grained Mafic Volcanic Rock) — igneous

Porphyritic Basalt

Porphyritic Fine-grained Mafic Volcanic Rock

Mahogany Obsidian (Obsidian (volcanic glass with hematite/magnetite inclusions)) — igneous

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

Sandstone (likely Arkosic) (Clastic Sedimentary Rock) — sedimentary

Sandstone (likely Arkosic)

Clastic Sedimentary Rock

Hag Stone (Perforated Sedimentary Rock) — sedimentary

Hag Stone

Perforated Sedimentary Rock

Sandstone Cobble (Clastic Sedimentary (Sandstone)) — sedimentary

Sandstone Cobble

Clastic Sedimentary (Sandstone)

Breciated Limestone with Calcite Veins (Sedimentary Breccia (CaCO3)) — sedimentary

Breciated Limestone with Calcite Veins

Sedimentary Breccia (CaCO3)

Shale or Siltstone (Sedimentary Rock (Siliciclastic)) — sedimentary

Shale or Siltstone

Sedimentary Rock (Siliciclastic)

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

Sandstone (likely Siltstone or fine-grained Sandstone)

Sedimentary Rock (Clastic)

Conglomerate (Clastic Sedimentary (Conglomerate)) — sedimentary

Conglomerate

Clastic Sedimentary (Conglomerate)

Limestone Breccia (Sedimentary Breccia (Calcareous)) — sedimentary

Limestone Breccia

Sedimentary Breccia (Calcareous)

Siltstone or Mudstone (Argillaceous sedimentary rock) — sedimentary

Siltstone or Mudstone

Argillaceous sedimentary rock

Sandstone (Quartz Sandstone (predominantly)) — Sedimentary

Sandstone

Quartz Sandstone (predominantly)

Shale creek bed (Shale (fine-grained clastic sedimentary rock)) — Sedimentary

Shale creek bed

Shale (fine-grained clastic sedimentary rock)

Basalt (Basalt (extrusive volcanic mafic rock)) — igneous

Basalt

Basalt (extrusive volcanic mafic rock)

Peridotite (Olivine/Peridot) (Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)) — igneous

Peridotite (Olivine/Peridot)

Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)

Basalt with Amygdaloidal Inclusions (Aphanitic Mafic Volcanic Rock (Basalt)) — igneous

Basalt with Amygdaloidal Inclusions

Aphanitic Mafic Volcanic Rock (Basalt)

Obsidian (Apache Tear) (Volcanic Glass (composed mainly of SiO2)) — igneous

Obsidian (Apache Tear)

Volcanic Glass (composed mainly of SiO2)

Obsidian (Black) (Obsidian (High-silica volcanic glass)) — igneous

Obsidian (Black)

Obsidian (High-silica volcanic glass)

Snowflake Obsidian (Volcanic glass containing Cristobalite (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Cristobalite (SiO2)

Sandstone or Quartzite (Arenite (if sedimentary) / Quartzite (if metamorphic)) — Sedimentary or Metamorphic

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Sedimentary or Metamorphic

Diabase (also known as Dolerite) (Diabase / Microgabbro) — igneous

Diabase (also known as Dolerite)

Diabase / Microgabbro

Basalt (Basalt (principally Plagioclase Feldspar and Pyroxene)) — igneous

Basalt

Basalt (principally Plagioclase Feldspar and Pyroxene)

Basalt with vesicles (Vesicular Basalt) — igneous

Basalt with vesicles

Vesicular Basalt

Grey Agate (Silicon Dioxide (SiO2) - variety: Agate/Chalcedony) — mineral

Grey Agate

Silicon Dioxide (SiO2) - variety: Agate/Chalcedony

Banded Agate (Cryptocrystalline Silicon Dioxide (SiO2)) — mineral

Banded Agate

Cryptocrystalline Silicon Dioxide (SiO2)

Obsidian (Obsidian (principally SiO2)) — igneous

Obsidian

Obsidian (principally SiO2)

Argetine Blue Agate (Chalcendony variant) (Silicon Dioxide (SiO₂)) — mineral

Argetine Blue Agate (Chalcendony variant)

Silicon Dioxide (SiO₂)

Basalt River Cobble (Basalt (Mafic Igneous Rock)) — igneous

Basalt River Cobble

Basalt (Mafic Igneous Rock)

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

Basalt River Pebble

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Vesicular Basalt (Amygdaloidal) (Amygdaloidal Basalt) — igneous

Vesicular Basalt (Amygdaloidal)

Amygdaloidal Basalt

Basalt (River Pebble) (Extrusive mafic igneous rock) — igneous

Basalt (River Pebble)

Extrusive mafic igneous rock

Agate (Silicon dioxide (SiO2)) — mineral

Agate

Silicon dioxide (SiO2)

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Diorite (Diorite (Intermediate plutonic rock)) — igneous

Diorite

Diorite (Intermediate plutonic rock)

Porphyry (Porphyritic Rhyolite or Andesite) — igneous

Porphyry

Porphyritic Rhyolite or Andesite

Basalt (Basalt) — igneous

Basalt

Basalt