Rock Identifier

Category

Organic (Non Geological)

Browse organic (non geological) specimens identified by the Rock Identifier community.

Chert (Black Chert/Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Black Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chalcedony / Agate with Botryoidal Quartz (Silicon Dioxide (SiO2)) — sedimentary

Chalcedony / Agate with Botryoidal Quartz

Silicon Dioxide (SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Baroque Pearl (and potentially a small Sapphire/Blue Topaz) (Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.) — Organic Gemstone (for pearl), Mineral (for sapphire/topaz)

Baroque Pearl (and potentially a small Sapphire/Blue Topaz)

Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.

Organic Gemstone (for pearl), Mineral (for sapphire/topaz)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

Chert / Flint (Cryptocrystalline Quartz (Silicon Dioxide, SiO2)) — sedimentary

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Chert (specifically Green Chert/Jasper) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (specifically Green Chert/Jasper)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Iron-stained) (Chert (primarily Microcrystalline Quartz, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (primarily Microcrystalline Quartz, SiO2)

Chert (Red/Pink Jasper subtype) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Red/Pink Jasper subtype)

Silicon Dioxide (SiO2)

Pyrite in Shale (Iron Sulfide (FeS2) in Argillaceous Shale) — sedimentary

Pyrite in Shale

Iron Sulfide (FeS2) in Argillaceous Shale

River Stone (Chert/Siltstone) (Cryptocrystalline Quartz (SiO2) with trace impurities) — sedimentary

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcedony replacement)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcedony replacement)

Mineral / Fossil

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Obsidian (Volcanic Glass (Silica / SiO2)) — igneous

Obsidian

Volcanic Glass (Silica / SiO2)

Pyritic Mudstone (Argillaceous rock (FeS2)) — sedimentary

Pyritic Mudstone

Argillaceous rock (FeS2)

Petrified Wood (Silicified wood (primarily SiO2)) — fossil

Petrified Wood

Silicified wood (primarily SiO2)

Sandstone (likely a river or beach pebble) (Sandstone (a clastic sedimentary rock)) — Sedimentary Rock

Sandstone (likely a river or beach pebble)

Sandstone (a clastic sedimentary rock)

Sedimentary Rock

Chert (specifically Flint or Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement) SiO2) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement) SiO2

Petrified Wood (Silicified Wood (primarily SiO₂)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO₂)

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

Pyrite (Pyrite (FeS2)) — Mineral

Pyrite

Pyrite (FeS2)

Black Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities) — igneous

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities

Tektite (Natural Impact Glass) — meteorite

Tektite

Natural Impact Glass

Flint (chert), likely brown flint (Microcrystalline quartz/chalcedony (SiO₂)) — sedimentary

Flint (chert), likely brown flint

Microcrystalline quartz/chalcedony (SiO₂)

Travertine / Tufa (Calcium Carbonate (CaCO3)) — sedimentary

Travertine / Tufa

Calcium Carbonate (CaCO3)

Quartz Geode (Silicon Dioxide (SiO2) in sedimentary host rock) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) in sedimentary host rock

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Obsidian (Obsidian (principally SiO2 with MgO and Fe3O4)) — igneous

Obsidian

Obsidian (principally SiO2 with MgO and Fe3O4)

Chert Nodule (Microcrystalline Silica (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Silica (SiO2)

Snowflake Obsidian (Obsidian with Cristobalite inclusions (70–75% SiO2)) — igneous

Snowflake Obsidian

Obsidian with Cristobalite inclusions (70–75% SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Chert (or Flint) (Chert (Sedimentary Cryptocrystalline Sio2)) — sedimentary

Chert (or Flint)

Chert (Sedimentary Cryptocrystalline Sio2)

Petrified Wood (Silicified wood (principally Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (principally Silicon Dioxide, SiO2)

Limonite (Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)) — Mineral

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)