Rock Identifier

Category

Mineral, Often A Rock Given Its Aggregate Nature

Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.

Chert (Iron-Stained) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone (likely Quartzose Sandstone) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (likely Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

Basalt (Extrusive Mafic Igneous Rock) — igneous

Basalt

Extrusive Mafic Igneous Rock

Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Sandstone (Painted) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Painted)

Arenite (primarily SiO2)

Scoria (Vesicular Basalt) (Scoria (Extrusive Igneous Rock)) — igneous

Scoria (Vesicular Basalt)

Scoria (Extrusive Igneous Rock)

Quartzite Pebble (River Rock) (Quartzite (primarily SiO2)) — metamorphic

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Turquoise (Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Sandstone (Banded) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (Banded)

Clastic sedimentary rock (primarily SiO2)

Sodalite (Sodalite, Na8(Al6Si6O24)Cl2) — mineral

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Basalt (Water-worn pebble) (Basalt (Mafic Extrusive Rock)) — igneous

Basalt (Water-worn pebble)

Basalt (Mafic Extrusive Rock)

Quartz Geode in Chert/Limestone Matrix (Silicon Dioxide (SiO2) within Sedimentary Host Rock) — sedimentary

Quartz Geode in Chert/Limestone Matrix

Silicon Dioxide (SiO2) within Sedimentary Host Rock

Prehnite (Prehnite - Ca2Al(AlSi3O10)(OH)2) — mineral

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Granite (likely a river or beach pebble) (Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)) — Igneous

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Yellow Quartzite (Iron-stained) (Quartzite (primarily SiO2 with Fe2O3 staining)) — metamorphic

Yellow Quartzite (Iron-stained)

Quartzite (primarily SiO2 with Fe2O3 staining)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Chert / Jasper / Agate (Chalcedony Group) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Basalt with Quartz Veining (Amygdaloidal Basalt (predominately SiO2 and (Na,Ca)(Si,Al)4O8)) — igneous

Basalt with Quartz Veining

Amygdaloidal Basalt (predominately SiO2 and (Na,Ca)(Si,Al)4O8)

Chert (Field Stone) (Chert (SiO2)) — sedimentary

Chert (Field Stone)

Chert (SiO2)

Basalt (Vesicular or Porphyritic) (Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine)) — igneous

Basalt (Vesicular or Porphyritic)

Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine)

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

Scoria (Vesicular Basalt)

Scoria (Extrusive Mafic Igneous Rock)

Arkosic Sandstone (Arkose (Clastic Sedimentary Rock)) — sedimentary

Arkosic Sandstone

Arkose (Clastic Sedimentary Rock)

Basalt (Polished pebble) (Basalt (Aphanitic mafic volcanic rock)) — igneous

Basalt (Polished pebble)

Basalt (Aphanitic mafic volcanic rock)

Chert Pebble/Nodule (Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)) — Sedimentary

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Sandstone (Quartzose Sandstone) (Arenite) — sedimentary

Sandstone (Quartzose Sandstone)

Arenite

Sandstone (Arenite (Sedimentary Rock)) — sedimentary

Sandstone

Arenite (Sedimentary Rock)

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

Basalt (River Stone)

Basalt (Mafic Extrusive Igneous Rock)

Red Sandstone (Arenite (ferruginous sandstone)) — sedimentary

Red Sandstone

Arenite (ferruginous sandstone)

Sandstone (with potential fossil inclusions) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with potential fossil inclusions)

Clastic sedimentary rock (primarily SiO2)

Conglomerate (Conglomerate (clastic sedimentary rock type)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock type)

Granite (Granite (Alkali-feldspar, Quartz, and Plagioclase composition)) — igneous

Granite

Granite (Alkali-feldspar, Quartz, and Plagioclase composition)

Chert Nodule (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Amethyst (Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities) — Mineral

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Quartz (likely Rose Quartz or Milky Quartz based on color) (Quartz (SiO2 - Silicon Dioxide)) — Mineral

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Gneiss (likely) (Gneiss) — Metamorphic

Gneiss (likely)

Gneiss

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

Smoky Quartz

Smoky Quartz (SiO2: Silicon Dioxide)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Basalt (Mafic volcanic rock (Basalt)) — igneous

Basalt

Mafic volcanic rock (Basalt)

Sandstone (Sandstone (lithified arenite/wacke)) — Sedimentary Rock

Sandstone

Sandstone (lithified arenite/wacke)

Sedimentary Rock

Jasper (yellow/cream variety) (SiO₂ (Cryptocrystalline Quartz)) — Sedimentary

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Sandstone (Arenite/Quartz Arenite) — sedimentary

Sandstone

Arenite/Quartz Arenite