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

Coral Rock

Rock Gypsum

Asphalt Rock

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

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

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Chert (Sedimentary Rock) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Sedimentary Rock)

Silicon Dioxide (SiO2)

Chert / Chalcedony (Silicon Dioxide (SiO2)) — sedimentary

Chert / Chalcedony

Silicon Dioxide (SiO2)

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)

Chert (often called Jasper in this color) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (often called Jasper in this color)

Microcrystalline quartz (SiO2)

Red Coral (Corallium rubrum) — mineral

Red Coral

Corallium rubrum

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

Chert / River Pebble

Microcrystalline Quartz (SiO2)

Agatized Chert / Chalcedony (Silicon Dioxide (SiO2)) — sedimentary

Agatized Chert / Chalcedony

Silicon Dioxide (SiO2)

Fossil bivalve shell (Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features) — fossil

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Jasper) (Microcrystalline Quartz (SiO2) with iron oxide impurities) — sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

Tree Agate (Silicon Dioxide (SiO2) with Dendritic Inclusions) — Mineral

Tree Agate

Silicon Dioxide (SiO2) with Dendritic Inclusions

Pyrite in Slate (Iron Sulfide (FeS2) in Slate host matrix) — metamorphic

Pyrite in Slate

Iron Sulfide (FeS2) in Slate host matrix

Sandstone (Arenicola (comprising mostly Quartz, SiO2)) — sedimentary

Sandstone

Arenicola (comprising mostly Quartz, SiO2)

Limestone (Calcareous sedimentary rock (CaCO3)) — sedimentary

Limestone

Calcareous sedimentary rock (CaCO3)

Chert (Pebble) (Microcrystalline to Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Pebble)

Microcrystalline to Cryptocrystalline Quartz (SiO2)

Weathered limestone or calcareous fossil fragment (Calcite-rich carbonate rock (CaCO₃), possibly fossiliferous limestone) — sedimentary

Weathered limestone or calcareous fossil fragment

Calcite-rich carbonate rock (CaCO₃), possibly fossiliferous limestone

Amber (Copal) (Succinite (fossilized resin)) — mineral

Amber (Copal)

Succinite (fossilized resin)

Shale (sub-type: Carbonaceous Shale) (Lutaceous Sedimentary Rock) — sedimentary

Shale (sub-type: Carbonaceous Shale)

Lutaceous Sedimentary Rock

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

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Fossilized Echinoid / Sea Urchin Internal Mold (Echinoidea internal cast (steinkern)) — fossil

Fossilized Echinoid / Sea Urchin Internal Mold

Echinoidea internal cast (steinkern)

Precious Red Coral (Corallium rubrum (Calcium Carbonate, CaCO3)) — gemstone

Precious Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Limestone with Fossil Inclusions (Sedimentary Carbonate Rock (CaCO3)) — sedimentary

Limestone with Fossil Inclusions

Sedimentary Carbonate Rock (CaCO3)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Sandstone Pebble (River Rock) (Sandstone (Quartz-rich sedimentary rock with iron oxide staining)) — sedimentary

Sandstone Pebble (River Rock)

Sandstone (Quartz-rich sedimentary rock with iron oxide staining)

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

Yellow Chert (Jasper)

Silicon Dioxide (SiO2)

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

Chert (Pebble)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

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

Chert (and Flint variant)

Microcrystalline Quartz (SiO2)

Likely chert or flint (Microcrystalline quartz (SiO₂), commonly called chert; exact identification requires testing) — sedimentary

Likely chert or flint

Microcrystalline quartz (SiO₂), commonly called chert; exact identification requires testing

Fossilized Shark Tooth (Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)) — sedimentary

Fossilized Shark Tooth

Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)

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

Moss Agate

Silicon Dioxide (SiO2) with inclusions

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)

Chalcedony in Matrix (likely Agatized Coral or Chert) (Silicon Dioxide (SiO2)) — sedimentary

Chalcedony in Matrix (likely Agatized Coral or Chert)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (Silicon Dioxide - SiO2)) — fossil

Petrified Wood

Silicified Wood (Silicon Dioxide - SiO2)

Shale (Shale (fine-grained clastic sedimentary rock)) — Sedimentary

Shale

Shale (fine-grained clastic sedimentary rock)

Petrified Wood (Silicified Wood (SiO2)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2)

Mineral / Fossil

Siltstone with Fossil Cast (Sedimentary Rock (Siltstone / Fine-grained Sandstone)) — sedimentary

Siltstone with Fossil Cast

Sedimentary Rock (Siltstone / Fine-grained Sandstone)

White limestone or chalky carbonate rock (Calcite-rich limestone; possibly chalk (CaCO₃)) — sedimentary

White limestone or chalky carbonate rock

Calcite-rich limestone; possibly chalk (CaCO₃)

Pyrite in Slate or Shale (Iron Sulfide (FeS2) in Argillaceous Matrix) — mineral

Pyrite in Slate or Shale

Iron Sulfide (FeS2) in Argillaceous Matrix