Rock Identifier

Category

Organic (Geological Interest)

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

Smurf Rock (Fictional Interpretation) (Cyanus Anthropomorphicus (Geologic Simulation)) — Artificial/Fantasy Object

Smurf Rock (Fictional Interpretation)

Cyanus Anthropomorphicus (Geologic Simulation)

Artificial/Fantasy Object

Iron-rich breccia or weathered ironstone (Hematite/goethite-bearing breccia; exact identification requires testing) — rock

Iron-rich breccia or weathered ironstone

Hematite/goethite-bearing breccia; exact identification requires testing

Orbicular granite (likely Rapakivi-type granite) (Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende) — igneous

Orbicular granite (likely Rapakivi-type granite)

Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Weathered limestone or calcareous sandstone (Calcite-dominated carbonate rock (CaCO₃), possibly fossiliferous limestone) — sedimentary

Weathered limestone or calcareous sandstone

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

Chert Pebble (Chert (SiO2)) — sedimentary

Chert Pebble

Chert (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (Jasper variation) (Chert (Microcrystalline Silicon Dioxide, SiO2)) — sedimentary

Chert (Jasper variation)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Limonite (Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)) — Mineral

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Quartz-rich rock, possibly milky quartz with chlorite or epidote (Quartz (SiO₂), with unidentified green inclusions) — mineral

Quartz-rich rock, possibly milky quartz with chlorite or epidote

Quartz (SiO₂), with unidentified green inclusions

Basalt with Quartz/Feldspar Vein (Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)) — igneous

Basalt with Quartz/Feldspar Vein

Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)

Banded gneiss pebble (Gneiss, likely quartz–feldspar–mica gneiss) — metamorphic

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Amber (Succinite (Approximate formula: C10H16O)) — mineral

Amber

Succinite (Approximate formula: C10H16O)

Weathered limestone or calcareous concretion (Calcite-rich limestone; predominantly calcium carbonate (CaCO₃)) — sedimentary

Weathered limestone or calcareous concretion

Calcite-rich limestone; predominantly calcium carbonate (CaCO₃)

Quartz-rich pegmatitic rock, possibly quartzite or granitic pegmatite (Quartz (SiO₂) with probable feldspar and iron-oxide staining; exact rock identification is uncertain from the photograph) — igneous

Quartz-rich pegmatitic rock, possibly quartzite or granitic pegmatite

Quartz (SiO₂) with probable feldspar and iron-oxide staining; exact rock identification is uncertain from the photograph

Quartz-rich metamorphic rock, likely quartzite (Quartzite; predominantly microcrystalline quartz (SiO₂), with possible feldspar, mica, and iron-oxide staining) — metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), with possible feldspar, mica, and iron-oxide staining

Black Freshwater Pearls (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Black Freshwater Pearls

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

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

Jasper

Silicon Dioxide (SiO2) with impurities

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

Chert (Jasper variation)

Silicon Dioxide (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Smooth River Pebble) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Smooth River Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chalcopyrite (CuFeS2) — mineral

Chalcopyrite

CuFeS2

Glauconitic Sandstone (Glauconitic Quartz Arenite) — sedimentary

Glauconitic Sandstone

Glauconitic Quartz Arenite

Chert (specifically Flint or Jasper variant) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Microcrystalline quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert

Cryptocrystalline Quartz (SiO2)

Desert Rose Fragment (Atypical) / Weathered Chert (Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy) — sedimentary

Desert Rose Fragment (Atypical) / Weathered Chert

Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy

Ambergris (Geological/Organic Specimen) (Ambra grisea (Produced by Physeter macrocephalus)) — organic material

Ambergris (Geological/Organic Specimen)

Ambra grisea (Produced by Physeter macrocephalus)

organic material

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

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Limestone with Fossil Fragment (Sedimentary carbonate rock (CaCO3)) — sedimentary

Limestone with Fossil Fragment

Sedimentary carbonate rock (CaCO3)

Gold-bearing quartz sulfide specimen (Native gold (Au) with quartz (SiO₂), likely associated with iron sulfides such as pyrite) — mineral

Gold-bearing quartz sulfide specimen

Native gold (Au) with quartz (SiO₂), likely associated with iron sulfides such as pyrite

Ferruginous Quartz (Iron-stained Quartz) (Silicon Dioxide with Iron Oxide (SiO2 with traces of Fe2O3/FeO(OH))) — mineral

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide with Iron Oxide (SiO2 with traces of Fe2O3/FeO(OH))

Iron-rich river pebble, likely weathered basalt or ironstone (Probable basalt (plagioclase–pyroxene rock) with iron-oxide/hydroxide weathering; exact identification requires testing) — igneous

Iron-rich river pebble, likely weathered basalt or ironstone

Probable basalt (plagioclase–pyroxene rock) with iron-oxide/hydroxide weathering; exact identification requires testing

Ferruginous Sandstone Concretion (Ironstone Phosphorite) (Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)) — sedimentary

Ferruginous Sandstone Concretion (Ironstone Phosphorite)

Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)

Fossilized Plant or Tree Bark (Lepidodendron or Sigillaria (example genera)) — sedimentary

Fossilized Plant or Tree Bark

Lepidodendron or Sigillaria (example genera)

Hypersthene (Hypersthene ((Mg,Fe)SiO₃)) — Mineral

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

Chert (Jasper/Flint variant) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint)

Silicon Dioxide (SiO2)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Black Jasper (Etched) (Silicon Dioxide (SiO2) with impurities) — mineral

Black Jasper (Etched)

Silicon Dioxide (SiO2) with impurities

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

Chert (Flint)

Microcrystalline Quartz (SiO2)