Rock Identifier

Category

Sedimentary (Volcanic)

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

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

Amethyst

SiO2 (Silicon Dioxide with iron impurities and irradiation)

Basalt (Basalt (Mafic Extrusive Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Rock)

Basalt with Granite Inclusions (Xenoliths) (Mafic igneous rock (Basalt) with Sialic minerals) — igneous

Basalt with Granite Inclusions (Xenoliths)

Mafic igneous rock (Basalt) with Sialic minerals

Vesicular Basalt (Extrusive mafic igneous rock (primarily Plagioclase feldspar and Pyroxene)) — igneous

Vesicular Basalt

Extrusive mafic igneous rock (primarily Plagioclase feldspar and Pyroxene)

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

Basalt River Cobble

Basalt (Mafic Extrusive Igneous Rock)

Yellow Quartz (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz

Silicon Dioxide (SiO2)

Granite (Granite (Phaneritic intrusive igneous rock)) — igneous

Granite

Granite (Phaneritic intrusive igneous rock)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Quartz Vein Rock (Silicon Dioxide (SiO2)) — Mineral

Quartz Vein Rock

Silicon Dioxide (SiO2)

Diorite (River Cobble) (Intermediate plutonic igneous rock) — igneous

Diorite (River Cobble)

Intermediate plutonic igneous rock

Greenstone (Greenschist / Meta-basalt) — metamorphic

Greenstone

Greenschist / Meta-basalt

Oceanside Agate (Orbicular Agate) (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Oceanside Agate (Orbicular Agate)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Black Sand (Magnetite Sand) (Magnetite (Fe3O4)) — mineral

Black Sand (Magnetite Sand)

Magnetite (Fe3O4)

Pumice (Pumice (a highly vesicular extrusive igneous rock)) — Igneous

Pumice

Pumice (a highly vesicular extrusive igneous rock)

Rhyolite (Rhyolite (Extrusive Felsic Igneous Rock)) — igneous

Rhyolite

Rhyolite (Extrusive Felsic Igneous Rock)

Diorite (River Rock) (Intermediate plutonic igneous rock) — igneous

Diorite (River Rock)

Intermediate plutonic igneous rock

Carnelian Agate (Silicon Dioxide (SiO2) - variety of Chalcedony) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

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

Basalt (Crushed Stone)

Basalt (Mafic Extrusive Igneous Rock)

Quartz Vein in Host Rock (Gossanous Matrtix) (Silicon Dioxide (SiO2) with iron oxides (Limonite/Hematite)) — mineral

Quartz Vein in Host Rock (Gossanous Matrtix)

Silicon Dioxide (SiO2) with iron oxides (Limonite/Hematite)

Scoria (Red Lava Rock) (Scoria (Extrusive Igneous Rock)) — Igneous

Scoria (Red Lava Rock)

Scoria (Extrusive Igneous Rock)

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

Basalt Beach Pebble

Basalt (Aphanitic Mafic Igneous Rock)

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Red Jasper (Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)) — Mineral

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)

Obsidian (Volcanic Glass (Extrusive Igneous Rock, primarily SiO2)) — igneous

Obsidian

Volcanic Glass (Extrusive Igneous Rock, primarily SiO2)

Sandstone or Mudstone with Iron Staining (Ferruginous Sandstone/Mudstone) — Sedimentary

Sandstone or Mudstone with Iron Staining

Ferruginous Sandstone/Mudstone

Pumice (Pumice (volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (volcanic glass with vesicular texture)

Mahogany Obsidian (Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)) — Igneous

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)

Banded Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Banded Agate

Cryptocrystalline Quartz (SiO2)

Banded Agate (Gray/White) (Silicon Dioxide (SiO2) - Chalcedony variety) — mineral

Banded Agate (Gray/White)

Silicon Dioxide (SiO2) - Chalcedony variety

Vesicular Basalt (Scoria) (Mafic extrusive volcanic rock (predominantly Plagioclase feldspar and Pyroxene)) — igneous

Vesicular Basalt (Scoria)

Mafic extrusive volcanic rock (predominantly Plagioclase feldspar and Pyroxene)

Quartz Vein in Sedimentary Rock (Silicon Dioxide (SiO2) with host Chert or Limestone) — mineral

Quartz Vein in Sedimentary Rock

Silicon Dioxide (SiO2) with host Chert or Limestone

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

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Prehnite on Basalt (Prehnite - Ca2Al(AlSi3O10)(OH)2) — mineral

Prehnite on Basalt

Prehnite - Ca2Al(AlSi3O10)(OH)2

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

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Snowflake Obsidian (Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)

Amethyst (Tumbled) (Quartz (Silicon Dioxide, SiO2) with iron impurities) — mineral

Amethyst (Tumbled)

Quartz (Silicon Dioxide, SiO2) with iron impurities

Crinoid Marble (Fossilized Limestone) (Crinoidal Limestone (comprising Calcite/Aragonite CaCO3)) — sedimentary

Crinoid Marble (Fossilized Limestone)

Crinoidal Limestone (comprising Calcite/Aragonite CaCO3)

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

Apache Tear (Obsidian)

Volcanic glass (SiO2 - Silicon Dioxide)

Basalt Pebble (Basalt (Aphanitic Mafic Volcanic Rock)) — igneous

Basalt Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

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

Obsidian

Obsidian (Volcanic Glass), primarily SiO2

Olivine (Peridotite) ((Mg, Fe)2SiO4 (Magnesium Iron Silicate)) — igneous

Olivine (Peridotite)

(Mg, Fe)2SiO4 (Magnesium Iron Silicate)