Rock Identifier

Category

Sedimentary (Volcanic)

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

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

Jasper

Jasper (a variety of Chalcedony, SiO2)

Opal (Hydrous silicon dioxide (SiO2·nH2O)) — mineral

Opal

Hydrous silicon dioxide (SiO2·nH2O)

Jasper (Silicon Dioxide (SiO2) - a variety of Chalcedony (Cryptocrystalline Quartz)) — Mineral

Jasper

Silicon Dioxide (SiO2) - a variety of Chalcedony (Cryptocrystalline Quartz)

Scoria (Red Lava Rock) (Scoria) — igneous

Scoria (Red Lava Rock)

Scoria

Andesite (Andesite) — igneous

Andesite

Andesite

Porphyritic Basalt (Chinese Writing Stone) (Porphyritic Basalt with Andalusite or Feldspar laths) — igneous

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt with Andalusite or Feldspar laths

Pink Dyed Agate (Pink Agate Slice) (Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz) — mineral

Pink Dyed Agate (Pink Agate Slice)

Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz

Mexican Crazy Lace Agate (Silicon Dioxide (SiO2) with iron and aluminum inclusions) — mineral

Mexican Crazy Lace Agate

Silicon Dioxide (SiO2) with iron and aluminum inclusions

Carnelian Agate (Silicon Dioxide with Hematite impurities (SiO2 + Fe2O3)) — mineral

Carnelian Agate

Silicon Dioxide with Hematite impurities (SiO2 + Fe2O3)

Chert (Chert (microcrystalline quartz)) — sedimentary

Chert

Chert (microcrystalline quartz)

Red Jasper (Jasper (a variety of Chalcedony, SiO₂)) — Mineraloid (cryptocrystalline quartz)

Red Jasper

Jasper (a variety of Chalcedony, SiO₂)

Mineraloid (cryptocrystalline quartz)

River Stone (likely Basalt or Chert) (Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt) — igneous/sedimentary

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

igneous/sedimentary

Painted River Pebble (likely Basalt or Greywacke) (Aphanitic Lithic Clast with Anthropogenic Pigment coating) — Sedimentary or Igneous

Painted River Pebble (likely Basalt or Greywacke)

Aphanitic Lithic Clast with Anthropogenic Pigment coating

Sedimentary or Igneous

Wood Jasper (Siliceous sedimentary rock (variety of Chert/Chalcedony)) — Sedimentary

Wood Jasper

Siliceous sedimentary rock (variety of Chert/Chalcedony)

Chert (Flint) (Chert (microcrystalline quartz)) — sedimentary

Chert (Flint)

Chert (microcrystalline quartz)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Jasper (likely a variety of Brecciated Jasper or a patterned variety) (Silicon dioxide (SiO2)) — Mineral

Jasper (likely a variety of Brecciated Jasper or a patterned variety)

Silicon dioxide (SiO2)

Chert (or Flint) (SiO2 (predominantly microcrystalline quartz)) — Sedimentary

Chert (or Flint)

SiO2 (predominantly microcrystalline quartz)

Red Jasper (Opaque Chalcedony) (Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions) — mineral

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Carnelian (Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)) — mineral

Carnelian

Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)

Bumblebee Jasper (Fossiliferous Volcanic Rock (composed of Calcium Carbonate, Manganese Oxides, and Arsenic Sulfides)) — igneous

Bumblebee Jasper

Fossiliferous Volcanic Rock (composed of Calcium Carbonate, Manganese Oxides, and Arsenic Sulfides)

Rhyolite (Rhyolite (High-silica volcanic rock)) — igneous

Rhyolite

Rhyolite (High-silica volcanic rock)

Basalt with Garnet inclusions (Basalt containing Nesosilicate (Garnet Group, likely Almandine Fe3Al2Si3O12)) — igneous

Basalt with Garnet inclusions

Basalt containing Nesosilicate (Garnet Group, likely Almandine Fe3Al2Si3O12)

Basalt (Basalt) — igneous

Basalt

Basalt

Greenstone (Metamorphosed Mafic Igneous Rock) — metamorphic

Greenstone

Metamorphosed Mafic Igneous Rock

Thunderegg (Ate Agate/Jasper Geode) (Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix) — sedimentary/igneous intermediary

Thunderegg (Ate Agate/Jasper Geode)

Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix

sedimentary/igneous intermediary

Bumble Bee Jasper (Volcanic Tuff (mixture of SiO2, CaCo3, S, and As2S3)) — igneous

Bumble Bee Jasper

Volcanic Tuff (mixture of SiO2, CaCo3, S, and As2S3)

Blue Agate (Dyed) (Silicon Dioxide (SiO2)) — Sedimentary (formed from silica deposits)

Blue Agate (Dyed)

Silicon Dioxide (SiO2)

Sedimentary (formed from silica deposits)

Pumice (Pumice (Vesicular Rhyolite/Andesite)) — igneous

Pumice

Pumice (Vesicular Rhyolite/Andesite)

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

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Fossilized Wood (Petrified Wood) (Silicified Wood (primarily quartz/chalcedony replacing organic matter)) — Sedimentary (with some aspects of mineral replacement)

Fossilized Wood (Petrified Wood)

Silicified Wood (primarily quartz/chalcedony replacing organic matter)

Sedimentary (with some aspects of mineral replacement)

Amethyst (Faceted Gemstone) (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst (Faceted Gemstone)

Silicon Dioxide (SiO2) with iron impurities

Porphyritic Basalt or Andesite (Porphyritic Basalt / Andesite) — Igneous

Porphyritic Basalt or Andesite

Porphyritic Basalt / Andesite

Sulfur on Aragonite (Sulfur (S) and Aragonite (CaCO3)) — Mineral

Sulfur on Aragonite

Sulfur (S) and Aragonite (CaCO3)

Jasper (yellow/cream variety) (SiO₂ (Cryptocrystalline Quartz)) — Sedimentary

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Carnelian (Carnelian (a variety of Chalcedony, SiO₂)) — Mineral

Carnelian

Carnelian (a variety of Chalcedony, SiO₂)

Jasper and Basalt Mix (Dark Chert/Basalt River Pebble) (Silicon Dioxide (SiO2) or Mafic extrusive igneous rock) — sedimentary or igneous

Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)

Silicon Dioxide (SiO2) or Mafic extrusive igneous rock

sedimentary or igneous

Concrete (Hydrated Portland Cement Aggregate Composite) — Anthropogenic Sedimentary (Man-made)

Concrete

Hydrated Portland Cement Aggregate Composite

Anthropogenic Sedimentary (Man-made)

Pumice (Vesicular Rhyolite / Glassy Igneous Rock) — igneous

Pumice

Vesicular Rhyolite / Glassy Igneous Rock

Pumice (Vesicular volcanic glass) — igneous

Pumice

Vesicular volcanic glass

Quartz Druzy on Basalt (Silicon Dioxide (SiO2) on Mafic Volcanic Rock) — Mineral on Igneous Rock

Quartz Druzy on Basalt

Silicon Dioxide (SiO2) on Mafic Volcanic Rock

Mineral on Igneous Rock

Magnetite (Iron Ore) (Magnetite (Fe3O4)) — mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)