Rock Identifier

Category

Sedimentary (Volcanic)

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

Shale or Argillite (Shale (sedimentary) / Argillite (metamorphic)) — Sedimentary or Metamorphic (low-grade)

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Sedimentary or Metamorphic (low-grade)

Mahogany Obsidian (Volcanic Glass with Hematite inclusions (SiO2)) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2)

Obsidian (Amorphous volcanic glass (primarily SiO2)) — igneous

Obsidian

Amorphous volcanic glass (primarily SiO2)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 dominated)

Mahogany Obsidian (Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)) — igneous

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)

Andesite Porphyry (Porphyritic Andesite (Intermediate volcanic rock)) — igneous

Andesite Porphyry

Porphyritic Andesite (Intermediate volcanic rock)

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Obsidian (Obsidian (Amorphous volcanic glass, predominantly SiO2)) — igneous

Obsidian

Obsidian (Amorphous volcanic glass, predominantly SiO2)

Quartz Veined Basalt (Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)) — igneous

Quartz Veined Basalt

Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)

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

Pumice

Pumice (volcanic glass with vesicular texture)

Vesicular Basalt (Lava Rock) (Aphanitic Mafic Igneous Rock) — igneous

Vesicular Basalt (Lava Rock)

Aphanitic Mafic Igneous Rock

Carnelian (Chalcedony (cryptocrystalline quartz), SiO2) — Mineral

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Chalk (Sedimentary Pebble) (Calcium Carbonate (CaCO3) - Biogenic Limestone) — sedimentary

Chalk (Sedimentary Pebble)

Calcium Carbonate (CaCO3) - Biogenic Limestone

Dyed Dragon Vein Agate (Silicon Dioxide (SiO2) with artificial dye) — mineral

Dyed Dragon Vein Agate

Silicon Dioxide (SiO2) with artificial dye

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

Peridot

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

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Rutilated Prehnite (Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions) — mineral

Rutilated Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions

Silver (Jewelry Specimen) (Native Silver (Chemical Formula: Ag)) — mineral

Silver (Jewelry Specimen)

Native Silver (Chemical Formula: Ag)

Basalt with Quartz/Feldspar Inclusions (Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining) — igneous

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

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

Red Scoria (Lava Rock)

Scoria (Vesicular Basalt/Andesite)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + oxide impurities)

Basalt (Water-worn Pebble) (Mafic Volcanic Rock (High in Fe and Mg)) — igneous

Basalt (Water-worn Pebble)

Mafic Volcanic Rock (High in Fe and Mg)

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic Extrusive volcanic rock)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive volcanic rock)

Banded Jasper (possibly "Picture Jasper") (Jasper (a microcrystalline variety of Quartz / Silicon Dioxide - SiO2)) — Sedimentary rock (specifically a chemical sedimentary rock, or a chert if considered purely mineral aggregate)

Banded Jasper (possibly "Picture Jasper")

Jasper (a microcrystalline variety of Quartz / Silicon Dioxide - SiO2)

Sedimentary rock (specifically a chemical sedimentary rock, or a chert if considered purely mineral aggregate)

Blue Chalcedony (Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)) — Mineral

Blue Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)

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

Pumice

Pumice (a highly vesicular felsic volcanic rock)

Basalt (Extrusive Mafic Igneous Rock) — igneous

Basalt

Extrusive Mafic Igneous Rock

Snowflake Obsidian (Volcanic Glass with Spherulitic Cristobalite (SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulitic Cristobalite (SiO2)

Obsidian (Volcanic Glass (70-75% SiO2)) — igneous

Obsidian

Volcanic Glass (70-75% SiO2)

Obsidian (Obsidian (Volcanic Glass, SiO2 + impurity)) — Igneous

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurity)

Fossiliferous Sedimentary Rock (Coquina/Limestone) (Fossiliferous Calcarenite / Bioclastic Limestone) — sedimentary

Fossiliferous Sedimentary Rock (Coquina/Limestone)

Fossiliferous Calcarenite / Bioclastic Limestone

Rhyolite (Rhyolite) — igneous

Rhyolite

Rhyolite

Olivine (Peridotite) (Olivine Group; (Mg, Fe)2SiO4) — igneous

Olivine (Peridotite)

Olivine Group; (Mg, Fe)2SiO4

Agate (Silicon dioxide (SiO2)) — mineral

Agate

Silicon dioxide (SiO2)

Black Onyx (Cryptocrystalline Chalcedony (SiO2)) — mineral

Black Onyx

Cryptocrystalline Chalcedony (SiO2)

Carnelian (Carnelian (SiO2)) — mineral

Carnelian

Carnelian (SiO2)

Vesicular Basalt with Secondary Mineral Inclusions (Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Vesicular Basalt with Secondary Mineral Inclusions

Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

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

Carnelian (Orange Agate/Chalcedony)

Silicon Dioxide (SiO2) - variety of Chalcedony

Basalt with Hematite staining (Extrusive mafic igneous rock with Fe2O3) — igneous

Basalt with Hematite staining

Extrusive mafic igneous rock with Fe2O3