Rock Identifier

Category

Organic Materia (Not A Rock Or Mineral)

Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Black Jasper (Silicon Dioxide (SiO2) with Carbonaceous inclusions) — sedimentary

Black Jasper

Silicon Dioxide (SiO2) with Carbonaceous inclusions

Chert (specifically Flint Arrowhead) (Silicon dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (specifically Flint Arrowhead)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Arenite (SiO2 based with various cements)) — sedimentary

Sandstone

Arenite (SiO2 based with various cements)

Banded Gneiss (Variety of Gneiss) (Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)) — Metamorphic Rock

Banded Gneiss (Variety of Gneiss)

Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)

Metamorphic Rock

Chert (Beach Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Milky Quartz (Water-worn Pebble) (Silicon Dioxide (SiO2)) — mineral

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Ocean Jasper (Spherulitic Chalcedony (SiO2)) — mineral

Ocean Jasper

Spherulitic Chalcedony (SiO2)

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

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Dyed Pink Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Dyed Pink Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Gneiss (River Cobble) (Gneiss (Foliated Metamorphic Rock)) — metamorphic

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

Sandstone (with Iron Oxide) (Arenite with Limonite/Hematite staining) — sedimentary

Sandstone (with Iron Oxide)

Arenite with Limonite/Hematite staining

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic volcanic rock)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Dalmatian Stone (often misnamed Dalmatian Jasper) (Aplite (with hornblende/arfvedsonite inclusions)) — igneous

Dalmatian Stone (often misnamed Dalmatian Jasper)

Aplite (with hornblende/arfvedsonite inclusions)

Granite Thin Section (Granitic rock (Phaneritic texture)) — igneous

Granite Thin Section

Granitic rock (Phaneritic texture)

Blue Chalcedony (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Schist (Mica Schist) — metamorphic

Schist

Mica Schist

Quartz Druzy Geode Fragment (Silicon Dioxide (SiO2)) — mineral

Quartz Druzy Geode Fragment

Silicon Dioxide (SiO2)

Amethyst (Tumbled) (Amethyst (Silicon Dioxide, SiO2 + Fe4+)) — mineral

Amethyst (Tumbled)

Amethyst (Silicon Dioxide, SiO2 + Fe4+)

Milky Quartz Vein in Host Rock (Silicon Dioxide (SiO2)) — Mineral

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Red Jasper (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Red Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

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

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite / Sandstone / Chert Mix (Silicon Dioxide (SiO2)) — sedimentary and metamorphic

Quartzite / Sandstone / Chert Mix

Silicon Dioxide (SiO2)

sedimentary and metamorphic

Granite (Granite (a common term for a felsic intrusive igneous rock)) — igneous

Granite

Granite (a common term for a felsic intrusive igneous rock)

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

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Conglomerate (Conglomerate (a clastic sedimentary rock)) — Sedimentary

Conglomerate

Conglomerate (a clastic sedimentary rock)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

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

Limonite (Iron Ore)

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

Granite (Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)) — igneous

Granite

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

Sandstone (Quartzose Sandstone) (Clastic Sedimentary Rock - Arenite) — sedimentary

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock - Arenite

Granite (Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)) — igneous

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)

Emerald In Matrix (Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium) — mineral

Emerald In Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Common Opal with Host Rock (Opal (Hydrated silica, SiO2·nH2O)) — mineral

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

Sandstone (with potential Quartzite characteristics) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with potential Quartzite characteristics)

Clastic sedimentary rock (primarily SiO2)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Sandstone (Arenite (high iron oxide content)) — sedimentary

Red Sandstone

Arenite (high iron oxide content)

Granitic Quartz with Feldspar (Granite (composed primarily of SiO2 and KAlSi3O8)) — igneous

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Dyed Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

River Stone (likely Siltstone or fine-grained Sandstone) (Clastic Sedimentary Rock (Lithic Wacke / Siltstone)) — sedimentary

River Stone (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock (Lithic Wacke / Siltstone)

Chert / Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper

Microcrystalline Quartz (SiO2)