Rock Identifier

Category

Organic (Mineraloid)

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

Chert (often called Flint or Agate nodule) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

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

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Lightly weathered variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Lightly weathered variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert / Flint

Silicon Dioxide (SiO₂)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Banded Chert with Quartz Veining (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert with Quartz Veining

Microcrystalline Quartz (SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert / Jasper

Silicon Dioxide (SiO₂)

Chert (and Chert-based Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — Sedimentary

Chert (and Chert-based Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossil Coral (Honeycomb Coral) (Favosites (extinct genus of Tabulate coral)) — sedimentary

Fossil Coral (Honeycomb Coral)

Favosites (extinct genus of Tabulate coral)

Chert (Gravel pebble) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Gravel pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper with Fossils (Silicified Fossiliferous Jasper (Chert variant, SiO2)) — sedimentary

Red Jasper with Fossils

Silicified Fossiliferous Jasper (Chert variant, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Amber (Succinite (C10H16O)) — mineral

Amber

Succinite (C10H16O)

Fossiliferous Limestone (Limestone (CaCO3 - Calcium Carbonate)) — sedimentary

Fossiliferous Limestone

Limestone (CaCO3 - Calcium Carbonate)

Dendritic Agate (Tree Agate) (Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions) — mineral

Dendritic Agate (Tree Agate)

Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions

Basaltic Tuff / Volcanic Breccia (Pyroclastic Breccia / Lithic Tuff) — igneous

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

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

Pyrite in Shale

Iron Disulfide (FeS2) in Argillaceous Shale

Shale (or Mudstone) (Siltstone/Argillite (composed mainly of clay and silt-sized particles)) — sedimentary

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

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

Green Moss Agate

Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite

Pink Opal (Amorphous Hydrous Silica (SiO2·nH2O)) — mineral

Pink Opal

Amorphous Hydrous Silica (SiO2·nH2O)

Ferruginous Sandstone (Ironstone) (Sedimentary rock with Limonite/Goethite cement) — sedimentary

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

Tree Agate (or Moss Agate) (Dendritic Agate (Silicon Dioxide - SiO2)) — mineral

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Pink Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Pink Opal

Hydrated Silica (SiO2·nH2O)

Amber (Succinite (specifically for Baltic amber; fossilized tree resin)) — Organic (Sedimentary-associated)

Amber

Succinite (specifically for Baltic amber; fossilized tree resin)

Organic (Sedimentary-associated)

Moss Agate and Hematite (Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)) — mineral

Moss Agate and Hematite

Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)

Coral Fossil (Scleractinia) (Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)) — sedimentary

Coral Fossil (Scleractinia)

Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)

Fossil Shell (Bivalve) (Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3) — sedimentary

Fossil Shell (Bivalve)

Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3

Natural or Cultured Pearl (Calcium Carbonate (Aragonite and Conchiolin), CaCO3) — Mineral (Organic)

Natural or Cultured Pearl

Calcium Carbonate (Aragonite and Conchiolin), CaCO3

Mineral (Organic)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Shale (Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)) — sedimentary

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Slate (Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)) — metamorphic

Slate

Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Shale or Slaty Mudstone (Argillaceous sedimentary rock) — sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

Fossilized Bone (Petrified Bone) (Permineralized Vertebrate Remains) — sedimentary

Fossilized Bone (Petrified Bone)

Permineralized Vertebrate Remains

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)

Tufa (Limestone) (Calcareous Tufa (CaCO3)) — sedimentary

Tufa (Limestone)

Calcareous Tufa (CaCO3)

Gastropod Steinkern (Fossil Snail Internal Mold) (Class Gastropoda (Internal Mold)) — sedimentary

Gastropod Steinkern (Fossil Snail Internal Mold)

Class Gastropoda (Internal Mold)

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

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxides