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.

Vesicular Basalt (commonly mistaken for Slag) (Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)) — igneous

Vesicular Basalt (commonly mistaken for Slag)

Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)

Granite (Intrusive Phaneritic Felsic Igneous Rock) — igneous

Granite

Intrusive Phaneritic Felsic Igneous Rock

Quartzite Pebbles (Meta-quartzite (SiO2)) — metamorphic

Quartzite Pebbles

Meta-quartzite (SiO2)

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

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Red Sandstone (Clastic sedimentary rock (primarily SiO2 with Fe2O3)) — sedimentary

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Quartz / Common Opal Transition (Silicon Dioxide (SiO2)) — mineral

Quartz / Common Opal Transition

Silicon Dioxide (SiO2)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Travertine (Calcareous Tufa (CaCO3)) — sedimentary

Travertine

Calcareous Tufa (CaCO3)

Slag (Metallurgical by-product) — Anthropogenic (Man-made material)

Slag

Metallurgical by-product

Anthropogenic (Man-made material)

Sandstone (Ferruginous Concretion) (Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement) — sedimentary

Sandstone (Ferruginous Concretion)

Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement

Breciated Chert (Brecciated Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Breciated Chert

Brecciated Chert (Microcrystalline Quartz, SiO2)

Quartz (Quartzite) (Silicon Dioxide (SiO2)) — mineral

Quartz (Quartzite)

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst Quartz

Silicon Dioxide (SiO2) with iron impurities

Red Jasper (Brecciated Jasper) (SiO2 (Silicon Dioxide) with Ferric Iron inclusions) — sedimentary

Red Jasper (Brecciated Jasper)

SiO2 (Silicon Dioxide) with Ferric Iron inclusions

Metaconglomerate (Metaconglomerate (Quartzite conglomerate)) — metamorphic

Metaconglomerate

Metaconglomerate (Quartzite conglomerate)

Sandstone (with potential Arkose/Lithic characteristics) (Arenite (Sedimentary rock composed of sand-sized grains)) — sedimentary

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Almandine Garnet (Iron aluminum silicate (Fe3Al2(SiO4)3)) — Mineral

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Chert / Flint (a variety of Chert) (Chert (SiO2)) — Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

Chert / Flint (a variety of Chert)

Chert (SiO2)

Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)

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

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartz with Iron Staining (Silicon Dioxide (SiO2) with Limonite/Hematite inclusions) — mineral

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Amethyst Geode/Cluster (Quartz (SiO2) - variety Amethyst) — Mineral

Amethyst Geode/Cluster

Quartz (SiO2) - variety Amethyst

Sandstone (Arenite (primarily SiO2 - Silicon Dioxide)) — sedimentary

Sandstone

Arenite (primarily SiO2 - Silicon Dioxide)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Malachite Coating on Host Rock (Malachite [Cu2CO3(OH)2]) — mineral

Malachite Coating on Host Rock

Malachite [Cu2CO3(OH)2]

Sandstone Clast (Arenite (primarily SiO2)) — sedimentary

Sandstone Clast

Arenite (primarily SiO2)

Chert Pebble with Quartz Veins (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Green Aventurine (Aventurine Quartz (SiO2 with inclusions)) — metamorphic

Green Aventurine

Aventurine Quartz (SiO2 with inclusions)

Quartz / Quartzite Fragment (Silicon Dioxide (SiO2)) — mineral / metamorphic

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

mineral / metamorphic

Undetermined Due to Blur (Possible Flesh-Tone Mineral) (Unknown (Insufficient Visual Clarity)) — Mineral

Undetermined Due to Blur (Possible Flesh-Tone Mineral)

Unknown (Insufficient Visual Clarity)

Specular Hematite (Hematite (Fe2O3)) — mineral

Specular Hematite

Hematite (Fe2O3)

River Cobble (likely Quartzite or Limestone) (SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)) — metamorphic or sedimentary

River Cobble (likely Quartzite or Limestone)

SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)

metamorphic or sedimentary

Slag (Anthropogenic Iron Silicate Glass) — mineral

Slag

Anthropogenic Iron Silicate Glass

Carnelian (Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)) — mineral

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Native Gold Nugget (Native Gold (Au)) — mineral

Native Gold Nugget

Native Gold (Au)

Ironstone Concretion / Limonite-stained Siltstone (Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)) — sedimentary

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)