Rock Identifier

Category

Sedimentary (Volcanic)

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

Basalt (Basalt (composition of Plagioclase feldspar and Pyroxene)) — igneous

Basalt

Basalt (composition of Plagioclase feldspar and Pyroxene)

Fire Agate (Rough) (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Fire Agate (Rough)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Agate (Silicon dioxide (SiO2)) — mineral

Agate

Silicon dioxide (SiO2)

Chert (specifically Gray/Blue-Gray Chert) (Chert (SiO2)) — sedimentary

Chert (specifically Gray/Blue-Gray Chert)

Chert (SiO2)

Agate (Moss or Plume Agate variety) (Silicon Dioxide (SiO2)) — mineral

Agate (Moss or Plume Agate variety)

Silicon Dioxide (SiO2)

Devil's Toenail (Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)) — sedimentary

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Amethyst (Amethyst (Silicon Dioxide, SiO2 + Fe)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 + Fe)

Pumice (Vesicular Rhyolite or Dacite) — igneous

Pumice

Vesicular Rhyolite or Dacite

Gold Sheen Obsidian (Obsidian (volcanic glass with SiO2 + gas inclusions)) — igneous

Gold Sheen Obsidian

Obsidian (volcanic glass with SiO2 + gas inclusions)

Pebble (likely Quartz or Chert) (SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.) — Sedimentary Rock

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Sedimentary Rock

Orca Agate (Blue Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Orca Agate (Blue Chalcedony)

Silicon Dioxide (SiO2)

Basalt (Mafic volcanic rock (Basalt)) — igneous

Basalt

Mafic volcanic rock (Basalt)

Golden Sheen Obsidian (Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen) — igneous

Golden Sheen Obsidian

Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen

Yellow Agate (Silicon Dioxide (SiO2)) — mineral

Yellow Agate

Silicon Dioxide (SiO2)

Basalt with Plagioclase Feldspar (Basalt (mafic extrusive igneous rock) with plagioclase feldspar phenocrysts) — Igneous

Basalt with Plagioclase Feldspar

Basalt (mafic extrusive igneous rock) with plagioclase feldspar phenocrysts

Black Onyx (Silicon dioxide (SiO2)) — mineral

Black Onyx

Silicon dioxide (SiO2)

Basalt (Mafic Igneous Rock) — igneous

Basalt

Mafic Igneous Rock

Quartz (Druzy) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy)

Silicon Dioxide (SiO2)

Snowflake Obsidian (Spherulitic Obsidian (primarily SiO2)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2)

Tektite (Indochinite) (Tektite (High-silica natural glass)) — mineraloid / impact glass

Tektite (Indochinite)

Tektite (High-silica natural glass)

mineraloid / impact glass

Porphyritic Basalt (with Lath-like Phenocrysts) (Porphyritic Basalt) — igneous

Porphyritic Basalt (with Lath-like Phenocrysts)

Porphyritic Basalt

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

Basalt

Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)

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

Peridot

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

Tektite (Indochinite) (Tektite (SiO2 + Al2O3, Glassy Melts)) — igneous

Tektite (Indochinite)

Tektite (SiO2 + Al2O3, Glassy Melts)

Andesite (Andesite (intermediate volcanic rock)) — igneous

Andesite

Andesite (intermediate volcanic rock)

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

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Sandstone (Water-worn Pebble) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Water-worn Pebble)

Clastic Sedimentary Rock (primarily SiO2)

Pumice (Pumice (Vesicular volcanic glass)) — igneous

Pumice

Pumice (Vesicular volcanic glass)

Druzy Quartz Geode (likely Smokey Quartz variety) (Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.) — Mineral structure/Rock

Druzy Quartz Geode (likely Smokey Quartz variety)

Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.

Mineral structure/Rock

Chert (Tan/Yellow variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Tan/Yellow variety)

Microcrystalline quartz (SiO2)

Sandstone (Ferruginous) (Arenite with Iron Oxide (Fe2O3) cement) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

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

Basalt Beach Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Petrified Wood (Silicified wood, primarily composed of Quartz (SiO2)) — Mineral, often found in sedimentary deposits

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Mineral, often found in sedimentary deposits

Obsidian (Extrusive igneous volcanic glass (rich in SiO2)) — igneous

Obsidian

Extrusive igneous volcanic glass (rich in SiO2)

Pumice (Pumice (Amorphous volcanic glass)) — igneous

Pumice

Pumice (Amorphous volcanic glass)

Pumice (Pumice (Vesicular volcanic glass)) — igneous

Pumice

Pumice (Vesicular volcanic glass)

Basalt (Water-worn Pebble) (Basalt (Mafic volcanic rock)) — Igneous

Basalt (Water-worn Pebble)

Basalt (Mafic volcanic rock)

Basalt (Basalt (composition predominately Plagioclase feldspar and Pyroxene)) — igneous

Basalt

Basalt (composition predominately Plagioclase feldspar and Pyroxene)

Agate Jasper (Cryptocrystalline Quartz (SiO2) with impurities) — mineral

Agate Jasper

Cryptocrystalline Quartz (SiO2) with impurities

Basalt (Basalt) — igneous

Basalt

Basalt

Pumice (Pumice (Vesicular Volcanic Glass)) — igneous

Pumice

Pumice (Vesicular Volcanic Glass)