Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Dendrite (Manganese Oxide Dendrites) (Psilomelane or Pyrolusite on Matrix (typically MnO2)) — mineral

Dendrite (Manganese Oxide Dendrites)

Psilomelane or Pyrolusite on Matrix (typically MnO2)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — metamorphic

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Ocean Jasper (Orbicular Jasper) (Silicon Dioxide (SiO2) with iron and magnesium inclusions) — mineral

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2) with iron and magnesium inclusions

Northern Shoveler Duck (Note: This is a biological specimen, not a rock) (Spatula clypeata) — not a rock (biological/ornithological)

Northern Shoveler Duck (Note: This is a biological specimen, not a rock)

Spatula clypeata

not a rock (biological/ornithological)

Limestone (Calcareous sedimentary rock (primarily CaCO3)) — sedimentary

Limestone

Calcareous sedimentary rock (primarily CaCO3)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Granite (Granite (Felsic Plutonic Rock)) — Igneous

Granite

Granite (Felsic Plutonic Rock)

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)

Sandstone (specifically Red Sandstone) (Arenite (primarily Quartz, SiO2)) — sedimentary

Sandstone (specifically Red Sandstone)

Arenite (primarily Quartz, SiO2)

Pumice (Pumice (Highly vesicular volcanic glass)) — igneous

Pumice

Pumice (Highly vesicular volcanic glass)

Gneiss (High-Grade Metamorphic Rock) (Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)) — metamorphic

Gneiss (High-Grade Metamorphic Rock)

Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)

Banded Sandstone (Liesegang Rings) (Sedimentary Arenite (SiO2 with FeO/Fe2O3 impurities)) — sedimentary

Banded Sandstone (Liesegang Rings)

Sedimentary Arenite (SiO2 with FeO/Fe2O3 impurities)

Jasper (Chocolate or Brown Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Jasper (Chocolate or Brown Jasper)

Silicon Dioxide (SiO2)

Sandstone with Quartz Veins (Arenite (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone with Quartz Veins

Arenite (primarily SiO2 with Fe2O3 staining)

Amazonite (K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)) — Mineral

Amazonite

K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)

Biotite Schist (Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)) — metamorphic

Biotite Schist

Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)

K2 Jasper (Beads) (Granodiorite with Azurite and Malachite) — igneous

K2 Jasper (Beads)

Granodiorite with Azurite and Malachite

Gneiss (High-grade Metamorphic Gneiss) — metamorphic

Gneiss

High-grade Metamorphic Gneiss

Scoria (Lava Rock) (Scoria (extrusive volcanic rock)) — igneous

Scoria (Lava Rock)

Scoria (extrusive volcanic rock)

Geode (unopened) (Calcedony-lined Geode (SiO2)) — sedimentary

Geode (unopened)

Calcedony-lined Geode (SiO2)

Jasper (Iron-stained Chert) (Silicon Dioxide (SiO2) with impurities of Hematite or Goethite) — sedimentary

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with impurities of Hematite or Goethite

Granite (Granite (Phaneritic intrusive igneous rock)) — igneous

Granite

Granite (Phaneritic intrusive igneous rock)

Red Sandstone (Arenite (Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone (Arenite (composed primarily of Quartz: SiO2)) — sedimentary

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Pearl (Biogenic Mineraloid) (Calcium carbonate (Aragonite) and Conchiolin, CaCO3) — mineral

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

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

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossil Coral (Favosites Honeycomb) (Favosites (Genus), Phylum Cnidaria, Class Anthozoa) — sedimentary

Fossil Coral (Favosites Honeycomb)

Favosites (Genus), Phylum Cnidaria, Class Anthozoa

Basalt (Mafic extrusive volcanic rock (composed primarily of Plagioclase feldspar and Pyroxene)) — igneous

Basalt

Mafic extrusive volcanic rock (composed primarily of Plagioclase feldspar and Pyroxene)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Arid Sandy Loam (Arenosols / Regosols) — sedimentary

Arid Sandy Loam

Arenosols / Regosols

Glauconitic Sandstone (Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2) — sedimentary

Glauconitic Sandstone

Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2

Sandstone (Ferruginous) (Arenite with Iron Oxides) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxides

Granite (Felsic Intrusive Igneous Rock) — igneous

Granite

Felsic Intrusive Igneous Rock

Pink Granite (River Pebble) (Phaneritic Felsic Igneous Rock) — igneous

Pink Granite (River Pebble)

Phaneritic Felsic Igneous Rock

Sandstone or Siltstone (Arenite (if sandstone)) — Sedimentary

Sandstone or Siltstone

Arenite (if sandstone)

Granodiorite (Granodiorite (Intermediate intrusive igneous rock)) — igneous

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Septarian Nodule (Septarian Concretion) — sedimentary

Septarian Nodule

Septarian Concretion

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood (SiO2)) — metamorphic

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2)

Sandstone (Ferruginous) (Ferruginous Sandstone (SiO2 with iron oxide cement)) — sedimentary

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with iron oxide cement)

Sandstone (with potential trace fossils) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with potential trace fossils)

Clastic sedimentary rock (primarily SiO2)

Chert (specifically Tan/Brown Chert) (Chert (SiO2)) — sedimentary

Chert (specifically Tan/Brown Chert)

Chert (SiO2)

Chert / Flint (Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂) — Mineral

Chert / Flint

Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂