Rock Identifier

Category

Sedimentary (Volcanic)

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

Basalt (River Pebble) (Basalt) — igneous

Basalt (River Pebble)

Basalt

Basalt River Stone (Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt River Stone

Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Pumice (Pumice (Alveolar Rhyolite / Dacite / Andesite)) — igneous

Pumice

Pumice (Alveolar Rhyolite / Dacite / Andesite)

Basalt Pebble (Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8) — igneous

Basalt Pebble

Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8

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

Basalt (River Pebble)

Extrusive mafic igneous rock

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment) (Quartz (SiO₂)) — Mineral

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Sandstone or Siltstone (Arenite (if sandstone)) — Sedimentary

Sandstone or Siltstone

Arenite (if sandstone)

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic Volcanic Rock)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Volcanic Rock)

Red Jasper (Jasper (a cryptocrystalline variety of Quartz, SiO₂)) — Sedimentary Rock

Red Jasper

Jasper (a cryptocrystalline variety of Quartz, SiO₂)

Sedimentary Rock

Basalt River Pebble (Basalt (Mafic volcanic rock)) — igneous

Basalt River Pebble

Basalt (Mafic volcanic rock)

Quartz in Basalt (Xenocryst) (Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock) — Igneous

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Basalt with Epidote (Flowerstone-like texture) (Amygdaloidal Basalt (silicate mineral inclusions)) — igneous

Basalt with Epidote (Flowerstone-like texture)

Amygdaloidal Basalt (silicate mineral inclusions)

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

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Dendritic Agate (or Dendritic Opal) (SiO2 (for Agate), SiO2·nH2O (for Opal)) — Mineral

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

Red Jasper (beads) (SiO₂ (Silicon Dioxide)) — Mineral, variety of chalcedony (microcrystalline quartz)

Red Jasper (beads)

SiO₂ (Silicon Dioxide)

Mineral, variety of chalcedony (microcrystalline quartz)

Pumice (Pumicite (Amorphous Volcanic Glass)) — Igneous

Pumice

Pumicite (Amorphous Volcanic Glass)

Pumice (Pumice (Amorphous volcanic glass)) — igneous

Pumice

Pumice (Amorphous volcanic glass)

Pumice (Pumicite) — igneous

Pumice

Pumicite

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

Obsidian

Volcanic Glass (SiO2 + minor impurities)

Thunderegg (Agate-filled Geode Node) (Silicon dioxide (SiO2) with various inclusions) — sedimentary/igneous association

Thunderegg (Agate-filled Geode Node)

Silicon dioxide (SiO2) with various inclusions

sedimentary/igneous association

Amygdaloidal Basalt (Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)) — igneous

Amygdaloidal Basalt

Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)

Basalt with Peridotite (Olivine) Xenolith (Olivine-rich Peridotite (Dunite) xenolith in Vesicular Basalt; chemical formula (Mg,Fe)2SiO4) — igneous

Basalt with Peridotite (Olivine) Xenolith

Olivine-rich Peridotite (Dunite) xenolith in Vesicular Basalt; chemical formula (Mg,Fe)2SiO4

Scoria (Lava Rock) (Extrusive Igneous Scoria (Vesicular Basalt)) — igneous

Scoria (Lava Rock)

Extrusive Igneous Scoria (Vesicular Basalt)

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

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Porphyry (Porphyritic Andesite/Basalt) — igneous

Porphyry

Porphyritic Andesite/Basalt

Amygdaloidal Basalt with Epidote/Chlorite (Basalt (containing (Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH)))) — igneous

Amygdaloidal Basalt with Epidote/Chlorite

Basalt (containing (Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH)))

Amygdaloidal Basalt (Amygdaloidal Basalt containing Zeolite and Calcite inclusions) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite and Calcite inclusions

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

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Porphyritic Basalt (River Rock) (Porphyritic Basalt) — igneous

Porphyritic Basalt (River Rock)

Porphyritic Basalt

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

Basalt (River Pebble)

Extrusive Mafic Igneous Rock

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Pumice (Pumice (extrusive volcanic rock)) — igneous

Pumice

Pumice (extrusive volcanic rock)

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

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

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Chalcedony (Banded/Mottled Variety) (Chalcedony (a cryptocrystalline variety of Quartz, SiO2)) — Mineral

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

Pumice (Vesicular volcanic glass) — igneous

Pumice

Vesicular volcanic glass

Ocean Jasper (Orbicular Jasper) (Spherulitic Chalcedony (SiO2)) — igneous

Ocean Jasper (Orbicular Jasper)

Spherulitic Chalcedony (SiO2)

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

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Scoria (Lava Rock) (Scoria (Mafic volcanic rock)) — igneous

Scoria (Lava Rock)

Scoria (Mafic volcanic rock)