Rock Identifier

Category

Sedimentary (Volcanic)

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

Concretion or Geode (unbroken) (Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.) — Sedimentary rock (specifically a concretion or possibly a geode)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Sedimentary rock (specifically a concretion or possibly a geode)

Scoria (with Iron Oxidation) (Vesicular Basalt / Scoria) — igneous

Scoria (with Iron Oxidation)

Vesicular Basalt / Scoria

Crushed Stone (Basalt/Gabbro) (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Crushed Stone (Basalt/Gabbro)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

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

Pumice

Pumice (a highly vesicular volcanic glass)

Basalt Pebble (Basalt) — igneous

Basalt Pebble

Basalt

Yellow Jasper (Silicon Dioxide (SiO2)) — sedimentary (microcrystalline silicate)

Yellow Jasper

Silicon Dioxide (SiO2)

sedimentary (microcrystalline silicate)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)) — Igneous

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)

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

Basalt (Vesicular)

Basalt (Mafic Extrusive Igneous Rock)

Porphyritic Basalt (Chinese Writing Stone) (Porphyritic Basalt or Porphyritic Andesite) — igneous

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt or Porphyritic Andesite

Basalt (Water-worn Pebble) (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt (Water-worn Pebble)

Basalt (Mafic Extrusive Igneous Rock)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Basalt with Secondary Mineral Inclusions (Amygdaloidal Basalt (Mafic volcanic rock, primarily Augite and Plagioclase)) — igneous

Basalt with Secondary Mineral Inclusions

Amygdaloidal Basalt (Mafic volcanic rock, primarily Augite and Plagioclase)

Porphyritic Basalt (Chinese Writing Stone) (Porphyritic Basalt or Porphyritic Andesite) — igneous

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt or Porphyritic Andesite

Jasper with Pyrite (Gold-colored inclusions) (Silicon Dioxide (SiO2) with Iron Disulfide (FeS2) inclusions) — sedimentary (chemical/biological)

Jasper with Pyrite (Gold-colored inclusions)

Silicon Dioxide (SiO2) with Iron Disulfide (FeS2) inclusions

sedimentary (chemical/biological)

Red Jasper (Red Jasper (variety of Chalcedony, SiO₂)) — Mineral

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

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

Amethyst (Chevron Amethyst)

Silicon Dioxide (SiO2) with iron impurities

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

Scoria (Basaltic Lava Rock)

Vesicular Basalt

Black Sapphire (Basaltic Blue Sapphire) (Corundum (Al2O3)) — mineral

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Red Agate (Carnelian) (Chalcedony (SiO2) with iron oxide inclusions) — mineral

Red Agate (Carnelian)

Chalcedony (SiO2) with iron oxide inclusions

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

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Nuummite (Antophyllite-Gedrite (Orthorhombic amphibole)) — metamorphic

Nuummite

Antophyllite-Gedrite (Orthorhombic amphibole)

Scoria (Red Lava Rock) (Scoria) — igneous

Scoria (Red Lava Rock)

Scoria

Scoria (Lava Rock) (Mafic Volcanic Scoria) — igneous

Scoria (Lava Rock)

Mafic Volcanic Scoria

Porphyritic Basalt (Flowerstone) (Porphyritic Basalt (Mafic volcanic rock)) — igneous

Porphyritic Basalt (Flowerstone)

Porphyritic Basalt (Mafic volcanic rock)

Basalt (Weathered/River worn) (Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)) — igneous

Basalt (Weathered/River worn)

Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Scoria (Lava Rock) (Scoria (Vesicular Basaltic Glass/Rock)) — igneous

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Glass/Rock)

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

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

Sunstone (Oregon Sunstone) (Labradorite (Feldspar variety) - (Ca, Na)(Al, Si)4O8) — mineral

Sunstone (Oregon Sunstone)

Labradorite (Feldspar variety) - (Ca, Na)(Al, Si)4O8

Scoria (Lava Rock) (Scoria) — igneous

Scoria (Lava Rock)

Scoria

Black Onyx (Silicon Dioxide (SiO2)) — mineral

Black Onyx

Silicon Dioxide (SiO2)

River Pebbles (Tumbled Quartz and Basalt) (Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt) — igneous and sedimentary

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

igneous and sedimentary

Scoria (Vesicular Basaltic Andesite/Scoria) — igneous

Scoria

Vesicular Basaltic Andesite/Scoria

Jasper (likely river-tumbled) (Jasper (Silica/Silicon Dioxide, SiO2)) — sedimentary (microcrystalline silicate)

Jasper (likely river-tumbled)

Jasper (Silica/Silicon Dioxide, SiO2)

sedimentary (microcrystalline silicate)

Basalt River Stone (Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)) — igneous

Basalt River Stone

Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)

Olivine in Basalt (Peridot) (Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) within Basalt (Rock)) — igneous

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) within Basalt (Rock)

Sandstone (Quartz-rich) (Arenite (SiO2)) — sedimentary

Sandstone (Quartz-rich)

Arenite (SiO2)

Porphyry (specifically Porphyritic Rhyolite or Andesite) (Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)) — igneous

Porphyry (specifically Porphyritic Rhyolite or Andesite)

Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)

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)

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

Basalt River Stone

Basalt (Aphanitic Mafic Volcanic Rock)

Golem (Megaton Pokémon (Lithos sapiens megalithos)) — igneous/sedimentary (Rock/Ground type)

Golem

Megaton Pokémon (Lithos sapiens megalithos)

igneous/sedimentary (Rock/Ground type)

Carnelian (Chalcedony variety) (SiO2 (Silicon Dioxide)) — Mineral

Carnelian (Chalcedony variety)

SiO2 (Silicon Dioxide)

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads) (Obsidian (volcanic glass, predominantly SiO2 with various impurities)) — Igneous

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads)

Obsidian (volcanic glass, predominantly SiO2 with various impurities)