Rock Identifier

Category

Organic (Geological Interest)

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

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz Vein in Pelite (Metamorphic Rock) (Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)) — metamorphic

Quartz Vein in Pelite (Metamorphic Rock)

Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)

Sandstone with Foliose Lichen (Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)) — sedimentary

Sandstone with Foliose Lichen

Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)

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

Chert (Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Basalt with Caliche Crust (Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating) — igneous

Basalt with Caliche Crust

Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating

Ferruginous Quartzite (also known as Ironstone or Gossan) (Ferruginous Quartzite with Goethite/Hematite staining) — metamorphic

Ferruginous Quartzite (also known as Ironstone or Gossan)

Ferruginous Quartzite with Goethite/Hematite staining

Mica Schist (Foliated Metamorphic Rock (rich in Muscovite or Biotite)) — metamorphic

Mica Schist

Foliated Metamorphic Rock (rich in Muscovite or Biotite)

Limonite (Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O) — mineral

Limonite

Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O

Limonite (after Pyrite Pseudomorph) (Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)) — mineral

Limonite (after Pyrite Pseudomorph)

Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)

Quartz with Iron Staining (Silicon Dioxide (SiO2) with Hematite inclusions) — mineral

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Hematite inclusions

Pearl (with Peridot) (Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4) — mineral

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Mica-rich Sandstone or Micaceous Schist Weathering (Micaceous Schist (Muscovite-Quartz composition)) — Metamorphic or Sedimentary depending on local grade

Mica-rich Sandstone or Micaceous Schist Weathering

Micaceous Schist (Muscovite-Quartz composition)

Metamorphic or Sedimentary depending on local grade

Milky Quartz with Iron Staining (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Quartz (Smoky/Milky variant) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky/Milky variant)

Silicon Dioxide (SiO2)

Gneiss (specifically a Granitic Gneiss) (Gneiss (Composition: Quartz, Feldspar, Mica)) — metamorphic

Gneiss (specifically a Granitic Gneiss)

Gneiss (Composition: Quartz, Feldspar, Mica)

Quartz with Iron Oxide Inclusions (SiO2 with Fe2O3 impurities) — Mineral

Quartz with Iron Oxide Inclusions

SiO2 with Fe2O3 impurities

Quartz-veined Basalt (Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein) — igneous

Quartz-veined Basalt

Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein

Milky Quartz with Iron Staining (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Quartz (Iron-Stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

Sandstone (Pebble) (Arenite / Clastic Sedimentary Rock) — sedimentary

Sandstone (Pebble)

Arenite / Clastic Sedimentary Rock

Ironstone Concretion (Siderite or Hematite-bonded Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite-bonded Concretion

Granite featuring Quartz Vein (Granite with hydrothermal silica (SiO2) intrusion) — igneous

Granite featuring Quartz Vein

Granite with hydrothermal silica (SiO2) intrusion

Fluorite-Gedrite in Quartz (Schist) (Fluorite (CaF2) with Gedrite in Quartz/Feldspar Matrix) — metamorphic

Fluorite-Gedrite in Quartz (Schist)

Fluorite (CaF2) with Gedrite in Quartz/Feldspar Matrix

Schist with Quartz/Mica (Mica Schist (primarily Muscovite and Quartz)) — Metamorphic

Schist with Quartz/Mica

Mica Schist (primarily Muscovite and Quartz)

Epidote (Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))) — mineral

Epidote

Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Ironstone Nodules / Siderite Concretion (Siderite (FeCO3) / Ferruginous Septarian Concretion) — sedimentary

Ironstone Nodules / Siderite Concretion

Siderite (FeCO3) / Ferruginous Septarian Concretion

Milk Quartz (or Milky Quartz) (Silicon Dioxide (SiO2)) — mineral

Milk Quartz (or Milky Quartz)

Silicon Dioxide (SiO2)

Yellow Quartzite (Quartzite (primarily SiO2)) — metamorphic

Yellow Quartzite

Quartzite (primarily SiO2)

Chert Nodule (Chert (SiO2)) — sedimentary

Chert Nodule

Chert (SiO2)

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)

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)

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

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

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))

Black Pearl (Tahitian Pearl) (Aragonite / Calcite (CaCO3) with Conchiolin) — mineral

Black Pearl (Tahitian Pearl)

Aragonite / Calcite (CaCO3) with Conchiolin

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)

Horse Chestnut (Buckeye seed) (Aesculus hippocastanum seed) — Organic (Non-geological)

Horse Chestnut (Buckeye seed)

Aesculus hippocastanum seed

Organic (Non-geological)

Pink Coral (Corallium rubrum (Calcium Carbonate, CaCO3)) — mineral

Pink Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Amber (Resinite / Fossilized Tree Resin) — mineral

Amber

Resinite / Fossilized Tree Resin

Quartz (in matrix) (Quartz (SiO₂)) — mineral

Quartz (in matrix)

Quartz (SiO₂)

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

Red Coral (Precious Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Freshwater Pearl (Aragonite / Biogenic Calcium Carbonate (CaCO3)) — mineral

Freshwater Pearl

Aragonite / Biogenic Calcium Carbonate (CaCO3)