Rock Identifier

Category

Biogenic Material

Browse biogenic material specimens identified by the Rock Identifier community.

Learn about Biogenic Material in the encyclopedia

Peat

Diatomite

Dunite

Limonite

Diamond

Peacock Opal

Metarhyolite

Rhodochrosite

Shell Opal

Madagascar Opal

Lavender Obsidian

Electric Blue Obsidian

Unakite (Altered Granite (Epidotized Granite)) — metamorphic

Unakite

Altered Granite (Epidotized Granite)

Schist (Greenschist / Mica Schist) (Foliated Metamorphic Rock (rich in chlorite, muscovite, and quartz)) — metamorphic

Schist (Greenschist / Mica Schist)

Foliated Metamorphic Rock (rich in chlorite, muscovite, and quartz)

Quartzite (Quartzite (SiO2 with minor impurities)) — metamorphic

Quartzite

Quartzite (SiO2 with minor impurities)

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

Milky Quartz / Chalcedony

Silicon Dioxide (SiO2)

Quartzite Pebble (Quartzite (SiO2)) — metamorphic

Quartzite Pebble

Quartzite (SiO2)

Sandstone (Feldspathic / Arkose) (Sandstone (SiO2 with variable mineral grains)) — sedimentary

Sandstone (Feldspathic / Arkose)

Sandstone (SiO2 with variable mineral grains)

Smoky Quartz (Polished) (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz (Polished)

Silicon Dioxide (SiO2)

Granitic Gneiss Pebble (Gneiss (felsic metamorphic rock)) — metamorphic

Granitic Gneiss Pebble

Gneiss (felsic metamorphic rock)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Yellow Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

River Pebble (Siltstone / Sandstone Pebble) (Sedimentary Rock (Quartz, Feldspar, Clay Minerals)) — sedimentary

River Pebble (Siltstone / Sandstone Pebble)

Sedimentary Rock (Quartz, Feldspar, Clay Minerals)

Crushed Limestone (Sedimentary Calcite/Dolomite Rock (CaCO3)) — sedimentary

Crushed Limestone

Sedimentary Calcite/Dolomite Rock (CaCO3)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Sandstone (Sandstone (composed mainly of Quartz, SiO2, and Feldspar)) — sedimentary

Sandstone

Sandstone (composed mainly of Quartz, SiO2, and Feldspar)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone (Sandstone (Quartzose/Feldspathic Sandstone)) — sedimentary

Sandstone

Sandstone (Quartzose/Feldspathic Sandstone)

Sandstone (Garden Boulder) (Sandstone (SiO2 dominated)) — sedimentary

Sandstone (Garden Boulder)

Sandstone (SiO2 dominated)

Red Sandstone (Arenite (Hematitic / Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Hematitic / Ferruginous Sandstone)

Carnelian Agate (Silicon Dioxide (SiO2) - Chalcedony with Iron Oxide impurities) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) - Chalcedony with Iron Oxide impurities

Quartz Beach Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Beach Pebble

Silicon Dioxide (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Banded Siltstone (Siltstone (primarily composed of silt-sized grains)) — sedimentary

Banded Siltstone

Siltstone (primarily composed of silt-sized grains)

Serpentine (Serpentinite) (Serpentine group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al)2O5(OH)4)) — metamorphic

Serpentine (Serpentinite)

Serpentine group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al)2O5(OH)4)

Sandstone (Pebble) (Sandstone (principally SiO2 with iron oxide impurities)) — sedimentary

Sandstone (Pebble)

Sandstone (principally SiO2 with iron oxide impurities)

Sandstone (Pebble) (Sandstone) — sedimentary

Sandstone (Pebble)

Sandstone

Fluorite (Calcium fluoride (CaF2)) — mineral

Fluorite

Calcium fluoride (CaF2)

Quartzite Pebble (Metaquartzite) — metamorphic

Quartzite Pebble

Metaquartzite

Sandstone (Arenite (SiO2 principal)) — sedimentary

Sandstone

Arenite (SiO2 principal)

Quartzite (Quartzite (chiefly SiO2)) — metamorphic

Quartzite

Quartzite (chiefly SiO2)

Basalt Cobble (Aphanitic Mafic Volcanic Rock (Basalt)) — igneous

Basalt Cobble

Aphanitic Mafic Volcanic Rock (Basalt)

Blue Calcite (Calcium Carbonate (CaCO3)) — mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Ferruginous) (Arenite with Iron-Oxide Cement) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Sandstone (Red/Brown) (Arenite (SiO2 dominated with iron oxides)) — sedimentary

Sandstone (Red/Brown)

Arenite (SiO2 dominated with iron oxides)

Quartzite (with Iron Staining) (Metamorphosed Sandstone (mainly SiO2 with Fe2O3/FeOOH impurities)) — metamorphic

Quartzite (with Iron Staining)

Metamorphosed Sandstone (mainly SiO2 with Fe2O3/FeOOH impurities)

Quartzite Pebble (Quartzite (SiO2)) — metamorphic

Quartzite Pebble

Quartzite (SiO2)

Sandstone (likely Arkosic or Ferruginous) (Arenite (SiO2 with iron oxides or feldspar)) — sedimentary

Sandstone (likely Arkosic or Ferruginous)

Arenite (SiO2 with iron oxides or feldspar)

Sandstone (Arenite (SiO2 with minor iron oxides)) — sedimentary

Sandstone

Arenite (SiO2 with minor iron oxides)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Sandstone (River Cobble) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2)

Quartz Veined Mudstone (Metasedimentary rock with Quartz (SiO2) veins) — metamorphic

Quartz Veined Mudstone

Metasedimentary rock with Quartz (SiO2) veins

Sandstone (Limonitic/Arkose) (Sandstone (primarily SiO2 with FeO(OH)·nH2O)) — sedimentary

Sandstone (Limonitic/Arkose)

Sandstone (primarily SiO2 with FeO(OH)·nH2O)