Rock Identifier

Category

Organic Structure (Not A Rock)

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

Learn about Organic Structure (Not A Rock) in the encyclopedia

Bituminous Shale

Bituminous Shale

Black Shale

Oil Shale

Petrified Wood

Crocodile Jasper

Crocodile Jasper

Opalized Wood

Rock Salt

Rock Gypsum

Coral Rock

Asphalt Rock

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Chert with Iron Oxide Staining (Microcrystalline Quartz (SiO2) with Limonite/Goethite staining) — sedimentary

Chert with Iron Oxide Staining

Microcrystalline Quartz (SiO2) with Limonite/Goethite staining

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Ironstone Concretion (Boxwork) (Siderite-Limonite Concretion (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Boxwork)

Siderite-Limonite Concretion (FeO(OH)·nH2O)

Anthracite Coal (Anthracite (Carbon-based metamorphic rock, 86-97% C)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Agate (Moss or Dendritic Agate) (Chalcedony (Silicon Dioxide, SiO2)) — mineral

Agate (Moss or Dendritic Agate)

Chalcedony (Silicon Dioxide, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Graphite-rich schist (likely graphite ore) (Graphite-bearing schist; predominantly graphitic carbon (C) with mica, quartz, and possible feldspar) — metamorphic

Graphite-rich schist (likely graphite ore)

Graphite-bearing schist; predominantly graphitic carbon (C) with mica, quartz, and possible feldspar

Chert (Jasper/Flint variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Concretion (likely iron-rich sandstone or claystone concretion) (Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing) — sedimentary

Concretion (likely iron-rich sandstone or claystone concretion)

Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing

Chert Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (often called Jasper or River Siltstone) (Chert (SiO2)) — sedimentary

Chert (often called Jasper or River Siltstone)

Chert (SiO2)

Fossil-bearing Sedimentary Rock (Sedimentum cum fossili) — fossil

Fossil-bearing Sedimentary Rock

Sedimentum cum fossili

Crushed Limestone (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Crushed Limestone

Sedimentary Calcium Carbonate (CaCO3)

Chert (specifically a weathered Chert nodule or fragment) (Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Chert (River Stone) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Stone)

Microcrystalline Quartz (SiO2)

Chert / River Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / River Pebble

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

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

Sandstone

Arenite (primarily composed of SiO2)

Possible fossilized shell or coral fragment (Indeterminate biogenic carbonate, likely calcite (CaCO₃)) — fossil

Possible fossilized shell or coral fragment

Indeterminate biogenic carbonate, likely calcite (CaCO₃)

Chert (Jasper type) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper type)

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper/Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Sandstone Concretion (Arenaceous concretion (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone Concretion

Arenaceous concretion (primarily SiO2 with Fe2O3 staining)

Red Coral (Corallium rubrum) — gemstone

Red Coral

Corallium rubrum

Manganese-coated Sandstone (Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)) — sedimentary

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Moss Agate (Chalcedony (Silicon Dioxide, SiO2) with inclusions) — mineral

Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with inclusions

Moss Agate (Chalcedony (SiO2) with inclusions of manganese or iron oxides) — mineral

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxides

Chert (Jasper/Flint variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Biogenic Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Limestone (CaCO3)

Black Marble (Recrystallized Limestone (CaCO3)) — metamorphic

Black Marble

Recrystallized Limestone (CaCO3)

Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Shungite (Non-crystalline carbon (high-carbon metamorphic rock)) — metamorphic

Shungite

Non-crystalline carbon (high-carbon metamorphic rock)

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

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Stromatolite (Biogenic Sedimentary Rock (composed predominantly of CaCO3)) — sedimentary

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Chert (Jasper) (Silicon dioxide (SiO2)) — sedimentary

Chert (Jasper)

Silicon dioxide (SiO2)

Chert Nodules (Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodules (Jasper)

Microcrystalline Quartz (SiO2)