Rock Identifier

Category

Organic Structure (Not A Rock)

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

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Glacial Erratic (Sandstone/Quartzite) (Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)) — sedimentary or metamorphic

Glacial Erratic (Sandstone/Quartzite)

Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)

sedimentary or metamorphic

Conglomerate (Conglomeratic Sandstone) — sedimentary

Conglomerate

Conglomeratic Sandstone

Quartzite with Quartz Veining (Quartzite (primarily SiO2)) — metamorphic

Quartzite with Quartz Veining

Quartzite (primarily SiO2)

Granite (Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).) — igneous

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Sandstone (Quartzose Sandstone) (Arenite (SiO2 principal component)) — sedimentary

Sandstone (Quartzose Sandstone)

Arenite (SiO2 principal component)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Granodiorite (containing Biotite and Quartz) (Granodiorite (Plagioclase-rich phaneritic intrusive rock)) — igneous

Granodiorite (containing Biotite and Quartz)

Granodiorite (Plagioclase-rich phaneritic intrusive rock)

Serpentinite (Serpentinite (complex silicate of magnesium, (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (complex silicate of magnesium, (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Brachiopod Fossil in Shale (Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)) — sedimentary

Brachiopod Fossil in Shale

Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)

Olivine in Basalt matrix (Peridotite (Mg, Fe)2SiO4) — igneous

Olivine in Basalt matrix

Peridotite (Mg, Fe)2SiO4

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Concrete Rubble with Aggregate (Hardened Portland Cement Paste with Coarse Aggregate) — Anthropogenic (Man-made)

Concrete Rubble with Aggregate

Hardened Portland Cement Paste with Coarse Aggregate

Anthropogenic (Man-made)

Sandstone Concretion (Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Grey Agate (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Grey Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Quartz (Milky/Common) (Quartz (Silicon Dioxide, SiO2)) — mineral

Quartz (Milky/Common)

Quartz (Silicon Dioxide, SiO2)

Grey Agate (Tumbled) (Silicon Dioxide (SiO2)) — mineral

Grey Agate (Tumbled)

Silicon Dioxide (SiO2)

Yellow Quartzite (Quartzite (primarily SiO2)) — metamorphic

Yellow Quartzite

Quartzite (primarily SiO2)

Sandstone (likely Arkosic) (Arenite (SiO2 with KAlSi3O8)) — sedimentary

Sandstone (likely Arkosic)

Arenite (SiO2 with KAlSi3O8)

Sandstone (Arenite (Clastic Sedimentary Rock)) — sedimentary

Sandstone

Arenite (Clastic Sedimentary Rock)

Granite Pebble (Granite (composed mainly of Quartz, Feldspar, and Mica)) — igneous

Granite Pebble

Granite (composed mainly of Quartz, Feldspar, and Mica)

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

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

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

Sandstone

Arenite (composed primarily of SiO2)

Basalt with Quartz/Calcite matrix (Basalt (SiO2 with Ca/Mg/Fe silicates) on a Mineral Matrix) — igneous

Basalt with Quartz/Calcite matrix

Basalt (SiO2 with Ca/Mg/Fe silicates) on a Mineral Matrix

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Granite (River Pebble) (Phaneritic intrusive igneous rock (Felsic)) — igneous

Granite (River Pebble)

Phaneritic intrusive igneous rock (Felsic)

Dyed Agate (Silicon Dioxide (SiO2)) — mineral

Dyed Agate

Silicon Dioxide (SiO2)

Basalt Porphyry (Porphyritic Basalt) — igneous

Basalt Porphyry

Porphyritic Basalt

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite (River Stone) (Quartzite (SiO2)) — metamorphic

Quartzite (River Stone)

Quartzite (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

River Pebble (Quartzite/Chert) (Quartzite with inclusions (SiO2)) — metamorphic

River Pebble (Quartzite/Chert)

Quartzite with inclusions (SiO2)

Serpentinite (Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt (Water-worn pebble) (Basalt (Aphanitic mafic volcanic rock)) — igneous

Basalt (Water-worn pebble)

Basalt (Aphanitic mafic volcanic rock)

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

Quartz Geode (Smoky Quartz)

Silicon Dioxide (SiO2)

Granite (Weathered) (Phaneritic Felsic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite (Weathered)

Phaneritic Felsic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Granite (Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, NaAlSi3O8)) — igneous

Granite

Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, NaAlSi3O8)

Pink Granite (Granite (Alkali-feldspar granite)) — igneous

Pink Granite

Granite (Alkali-feldspar granite)