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

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Fossilized Coral (Rugose coral / Tabulate coral (Calcium carbonate, CaCO3)) — fossil

Fossilized Coral

Rugose coral / Tabulate coral (Calcium carbonate, CaCO3)

Ironstone Concretion / Hematite Nodules (Ferruginous Sedimentary Rock (primarily Hematite Fe2O3 and Goethite FeO(OH))) — sedimentary

Ironstone Concretion / Hematite Nodules

Ferruginous Sedimentary Rock (primarily Hematite Fe2O3 and Goethite FeO(OH))

Shale (with minor calcite veining) (Clastic sedimentary rock (primarily clay minerals and quartz)) — sedimentary

Shale (with minor calcite veining)

Clastic sedimentary rock (primarily clay minerals and quartz)

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

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Bituminous Coal (Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)) — sedimentary

Bituminous Coal

Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)

Shale or Argillite (Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)) — Sedimentary or Metamorphic (low grade)

Shale or Argillite

Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)

Sedimentary or Metamorphic (low grade)

Blue Agate (Tumbled and Dyed) (Silicon Dioxide (SiO2) with likely organic dyes) — mineral

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Moss Agate (Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide) — mineral

Moss Agate

Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide

Chert (Flint Nodule) (Microcrystalline and Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint Nodule)

Microcrystalline and Cryptocrystalline Quartz (SiO2)

Banded Chert / Sandstone Pebble (Microcrystalline Quartz (SiO2) / Silicified Sandstone) — sedimentary

Banded Chert / Sandstone Pebble

Microcrystalline Quartz (SiO2) / Silicified Sandstone

Amber (Succinite (specifically for Baltic Amber), Formula: C10H16O) — Organic Gemstone (often associated with Sedimentary sequences)

Amber

Succinite (specifically for Baltic Amber), Formula: C10H16O

Organic Gemstone (often associated with Sedimentary sequences)

Black Chert (Carbonaceous Chert (Silicon dioxide, SiO2)) — sedimentary

Black Chert

Carbonaceous Chert (Silicon dioxide, SiO2)

Graphite-bearing schist (probable) (Graphite–quartz–mica schist; chiefly graphite (C), quartz (SiO₂), and mica) — metamorphic

Graphite-bearing schist (probable)

Graphite–quartz–mica schist; chiefly graphite (C), quartz (SiO₂), and mica

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

Chert / River Pebble

Microcrystalline Silica (SiO2)

Amber (Cherry or Red variety) (Succinite (with various trace amounts of organic compounds)) — Organic Gemstone (not a rock)

Amber (Cherry or Red variety)

Succinite (with various trace amounts of organic compounds)

Organic Gemstone (not a rock)

Petrified Wood (Silicified wood / Xylopal) — fossil

Petrified Wood

Silicified wood / Xylopal

Green Moss Agate (Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite) — sedimentary

Green Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Red Coral (Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)) — Mineraloid (Organic Gemstone)

Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)

Mineraloid (Organic Gemstone)

Fossil Coral (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Chert (Green variety) (Microcrystalline Opaline/Quartz (SiO2)) — sedimentary

Chert (Green variety)

Microcrystalline Opaline/Quartz (SiO2)

Quartz Geode in Chert/Limestone Matrix (Silicon Dioxide (SiO2) within Sedimentary Host Rock) — sedimentary

Quartz Geode in Chert/Limestone Matrix

Silicon Dioxide (SiO2) within Sedimentary Host Rock

Petrified Wood (Silicified Wood (primarily Quartz / Chalcedony: SiO2)) — metamorphic

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Red Jasper (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Conglomerate (Conglomerate) — Sedimentary Rock

Conglomerate

Conglomerate

Sedimentary Rock

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

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

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

Banded Chert (or River Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

Chert (Arrowhead or Projectile Point) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Arrowhead or Projectile Point)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Septarian Nodule (Septarian Concretion (Calcite, Aragonite, and Limestone)) — sedimentary

Septarian Nodule

Septarian Concretion (Calcite, Aragonite, and Limestone)

Amber (Succinite (with formula approximately C10H16O)) — Organic mineraloid

Amber

Succinite (with formula approximately C10H16O)

Organic mineraloid

Moss Agate (Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides) — Mineral (Variety of Chalcedony)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides

Mineral (Variety of Chalcedony)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Nodule / Geode fragment) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Graphite-veined Quartzite (Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)) — metamorphic

Graphite-veined Quartzite

Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)

Coarse Sand or Fine Gravel (Detrital Sedimentary Fragments (mostly SiO2)) — sedimentary

Coarse Sand or Fine Gravel

Detrital Sedimentary Fragments (mostly SiO2)

Limestone Pebble (Calcite-rich Sedimentary Rock (CaCO3)) — sedimentary

Limestone Pebble

Calcite-rich Sedimentary Rock (CaCO3)

Fossilized Horn Coral (Rugosa (Rugose Coral)) — fossil

Fossilized Horn Coral

Rugosa (Rugose Coral)

Moss agate bracelet (Chalcedony (microcrystalline quartz, SiO₂) with chlorite/amphibole inclusions) — gemstone

Moss agate bracelet

Chalcedony (microcrystalline quartz, SiO₂) with chlorite/amphibole inclusions

Chert (Quartz Variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Quartz Variety)

Silicon Dioxide (SiO2)

Red Sandstone with Reduction Spot (Quartzose Sandstone with a Leach/Reduction Spot) — sedimentary

Red Sandstone with Reduction Spot

Quartzose Sandstone with a Leach/Reduction Spot

Graphite (Graphite (Carbon, C)) — Mineral

Graphite

Graphite (Carbon, C)