Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

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

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone

Clastic sedimentary rock (primarily SiO2)

Jasper (Silicon dioxide (SiO2)) — sedimentary

Jasper

Silicon dioxide (SiO2)

Yellow Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Milky Quartz with Iron Inclusions (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Granitic Pegmatite (Pegmatitic Granite) — igneous

Granitic Pegmatite

Pegmatitic Granite

Sandstone (likely River-tumbled Picture Sandstone) (Arenite (predominantly SiO2 with iron oxide impurities)) — sedimentary

Sandstone (likely River-tumbled Picture Sandstone)

Arenite (predominantly SiO2 with iron oxide impurities)

Quartz with Limonite Staining (Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)) — Mineral

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Olivine Basalt (Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)) — igneous

Olivine Basalt

Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)

Fire Opal (in matrix) (Hydrated Silica (SiO2·nH2O)) — Mineraloid

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

River Rock (likely Quartzite or Chert) (Quartzite (primarily SiO2)) — metamorphic

River Rock (likely Quartzite or Chert)

Quartzite (primarily SiO2)

Basalt (Basalt) — igneous

Basalt

Basalt

Quartz (Milky or Smoky variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Smoky variety)

Silicon Dioxide (SiO2)

Ferruginous Sandstone (Red Sandstone) (Arenite with Hematite/Limonite cement) — sedimentary

Ferruginous Sandstone (Red Sandstone)

Arenite with Hematite/Limonite cement

Yellow Quartzite Pebble (Quartzite (primarily SiO2)) — metamorphic

Yellow Quartzite Pebble

Quartzite (primarily SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Ruby in Zoisite with Hornblende (Anyolite (Ruby: Al2O3, Zoisite: Ca2Al3(SiO4)3(OH))) — metamorphic

Ruby in Zoisite with Hornblende

Anyolite (Ruby: Al2O3, Zoisite: Ca2Al3(SiO4)3(OH))

Serpentinite (Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4) — metamorphic

Serpentinite

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Serpentinite (Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4) — metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Dyed Agate (Chalcedony (Silicon Dioxide, SiO2)) — mineral

Dyed Agate

Chalcedony (Silicon Dioxide, SiO2)

Gneiss with Quartz Vein (Gneiss containing Quartz (SiO2) filler) — metamorphic

Gneiss with Quartz Vein

Gneiss containing Quartz (SiO2) filler

Jasper (with Agate/Chalcedony inclusions) (Silicon Dioxide (SiO2)) — sedimentary

Jasper (with Agate/Chalcedony inclusions)

Silicon Dioxide (SiO2)

Quartzite Pebble (River Rock) (Quartzite (mainly SiO2)) — metamorphic

Quartzite Pebble (River Rock)

Quartzite (mainly SiO2)

River Stone (likely Quartzite or Chert) (Recrystallized Silicon Dioxide (SiO2)) — metamorphic

River Stone (likely Quartzite or Chert)

Recrystallized Silicon Dioxide (SiO2)

Granite Gneiss (Felsic Gneiss) — metamorphic

Granite Gneiss

Felsic Gneiss

Jasper (Red/Yellow) (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper (Red/Yellow)

Silicon Dioxide (SiO2) with impurities

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — Mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Sandstone with Ironstone Concretion (Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))) — sedimentary

Sandstone with Ironstone Concretion

Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))

Obsidian (Amorphous Volcanic Glass (primarily SiO2)) — igneous

Obsidian

Amorphous Volcanic Glass (primarily SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Serpentinite (Serpentinite (group of hydrous magnesium iron phyllosilicates)) — metamorphic

Serpentinite

Serpentinite (group of hydrous magnesium iron phyllosilicates)

Mahogany Obsidian (Volcanic Glass with Hematite or Magnetite inclusions (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite or Magnetite inclusions (SiO2 + Fe2O3)

Bauxite (Bauxite (Al2O3·nH2O)) — sedimentary

Bauxite

Bauxite (Al2O3·nH2O)

Garnet Schist or Garnet-bearing Quartzite (Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)) — metamorphic

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Vesicular Basalt (Scoria) (Vesicular Basalt) — igneous

Vesicular Basalt (Scoria)

Vesicular Basalt

Blue Tiger's Eye (Crocidolite in Quartz (altered)) — Mineral

Blue Tiger's Eye

Crocidolite in Quartz (altered)

River Pebbles (Stream-rounded rocks) (Fluvial Detritus (varied mineralogy)) — Mixed (predominantly sedimentary and igneous)

River Pebbles (Stream-rounded rocks)

Fluvial Detritus (varied mineralogy)

Mixed (predominantly sedimentary and igneous)

Labradorite (Larvikite variety) (Plagioclase Feldspar (Na,Ca)(Al,Si)4O8 with Monzonite/Syenite matrix) — igneous

Labradorite (Larvikite variety)

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8 with Monzonite/Syenite matrix