Rock Identifier

Category

Sedimentary (Secondary Formation)

Browse sedimentary (secondary formation) specimens identified by the Rock Identifier community.

Fossil Brachiopod or Mollusk Cast (Phylum Brachiopoda / Mollusca internal mold) — fossil

Fossil Brachiopod or Mollusk Cast

Phylum Brachiopoda / Mollusca internal mold

Sandstone Pebble (Sedimentary Rock (Quartzose Sandstone)) — sedimentary

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Sandstone (Sedimentary Clastic Rock (Quartz Arenite)) — sedimentary

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Malachite (Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)) — Mineral

Malachite

Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)

Milky Quartz (Tumbled Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Milky Quartz (Tumbled Chalcedony)

Silicon Dioxide (SiO2)

Limonite/Goethite on Shale (Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock) — sedimentary

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Dinosaur Claw Fossil (Fossilized Theropod Claw (Vertebrate Palaeontological Specimen)) — fossil

Dinosaur Claw Fossil

Fossilized Theropod Claw (Vertebrate Palaeontological Specimen)

Drill-core rock, likely foliated metamorphic rock (Indeterminate from the photograph; possibly slate, phyllite, or schist) — metamorphic

Drill-core rock, likely foliated metamorphic rock

Indeterminate from the photograph; possibly slate, phyllite, or schist

Banded Agate (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Agate

Cryptocrystalline Quartz (SiO2)

Limonite Geode / Ironstone Concretion (Hydrated Iron Oxide (FeO(OH)·nH2O)) — sedimentary

Limonite Geode / Ironstone Concretion

Hydrated Iron Oxide (FeO(OH)·nH2O)

Green Onyx (Banded Calcite) (Travertine (CaCO3 - Calcium Carbonate)) — sedimentary

Green Onyx (Banded Calcite)

Travertine (CaCO3 - Calcium Carbonate)

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

Chert (Nodular)

Chert (Microcrystalline Quartz, SiO2)

Chert (Jasper/Agate variant) (Microcrystalline Quartz (SiO2) with iron oxide inclusions) — sedimentary

Chert (Jasper/Agate variant)

Microcrystalline Quartz (SiO2) with iron oxide inclusions

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

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Jasper Breccia (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper Breccia

Silicon Dioxide (SiO2) with impurities

Likely ironstone or iron-rich rock fragment (Iron-oxide-rich sedimentary material, chiefly hematite (α-Fe₂O₃) and/or goethite (FeO(OH)); exact identification is not possible from the image) — sedimentary

Likely ironstone or iron-rich rock fragment

Iron-oxide-rich sedimentary material, chiefly hematite (α-Fe₂O₃) and/or goethite (FeO(OH)); exact identification is not possible from the image

Possible fossil-bearing pebble (Unidentified fine-grained sedimentary rock; the small orange feature may be a fossil or mineral inclusion) — sedimentary

Possible fossil-bearing pebble

Unidentified fine-grained sedimentary rock; the small orange feature may be a fossil or mineral inclusion

Iron-rich sulfide ore (likely pyrite-bearing rock) (Likely pyrite (FeS₂) with dark host rock; exact identification is uncertain from the image alone.) — mineral

Iron-rich sulfide ore (likely pyrite-bearing rock)

Likely pyrite (FeS₂) with dark host rock; exact identification is uncertain from the image alone.

Yellow Calcite (Polished) (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite (Polished)

Calcium Carbonate (CaCO3)

Optical Calcite (Calcium Carbonate (CaCO3)) — mineral

Optical Calcite

Calcium Carbonate (CaCO3)

Quartz with inclusions (SiO2) — mineral

Quartz with inclusions

SiO2

Glauconitic Sandstone (or Greenstone) (Glauconitic Sandstone with Quartz) — sedimentary

Glauconitic Sandstone (or Greenstone)

Glauconitic Sandstone with Quartz

Small white mineral fragment (Indeterminate; possibly quartz, calcite, or feldspar) — mineral

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Yellow Quartz (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz

Silicon Dioxide (SiO2)

Iron-rich rock, likely hematite/goethite-rich ironstone (Hematite (α-Fe₂O₃), possibly mixed with goethite (FeO(OH)) and gangue minerals) — mineral

Iron-rich rock, likely hematite/goethite-rich ironstone

Hematite (α-Fe₂O₃), possibly mixed with goethite (FeO(OH)) and gangue minerals

Likely weathered quartz-bearing rock fragment (Provisional identification: quartz-rich sandstone or microcrystalline quartz (SiO₂)) — mineral

Likely weathered quartz-bearing rock fragment

Provisional identification: quartz-rich sandstone or microcrystalline quartz (SiO₂)

Small weathered mineral/rock fragment (Uncertain from image; possibly quartz-rich sandstone or a feldspar-bearing rock) — mineral

Small weathered mineral/rock fragment

Uncertain from image; possibly quartz-rich sandstone or a feldspar-bearing rock

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Sandstone (Picture Sandstone) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Picture Sandstone)

Arenite (primarily SiO2)

Limestone (Calcitic Limestone (CaCO3)) — sedimentary

Limestone

Calcitic Limestone (CaCO3)

Limestone (River Pebble) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (River Pebble)

Calcium Carbonate (CaCO3)

Sandstone (Arenite (SiO2 based with mineral cement)) — sedimentary

Sandstone

Arenite (SiO2 based with mineral cement)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Waterworn pebble, possibly iron-rich basalt or river stone (Unidentified lithic clast; composition cannot be determined reliably from the image) — igneous

Waterworn pebble, possibly iron-rich basalt or river stone

Unidentified lithic clast; composition cannot be determined reliably from the image

Likely weathered metamorphic rock (quartzite or schist) (Quartz-rich foliated metamorphic rock; exact identification requires testing) — metamorphic

Likely weathered metamorphic rock (quartzite or schist)

Quartz-rich foliated metamorphic rock; exact identification requires testing

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Red Jasper

Silicon Dioxide (SiO2) with Iron inclusions

Geode (Chert or Quartz Nodule) (Silicon Dioxide (SiO2)) — sedimentary

Geode (Chert or Quartz Nodule)

Silicon Dioxide (SiO2)

Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)