Rock Identifier

Category

Organic Structure (Not A Rock)

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

Sandstone (Greywacke) (Arenite / Wacke (Mainly SiO2 with various lithic fragments)) — sedimentary

Sandstone (Greywacke)

Arenite / Wacke (Mainly SiO2 with various lithic fragments)

Ferruginous Sandstone (Sandstone (arenite) with Limonite/Goethite cement) — sedimentary

Ferruginous Sandstone

Sandstone (arenite) with Limonite/Goethite cement

Chert (Green variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

Sandstone (with Iron concretions/staining) (Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)) — sedimentary

Sandstone (with Iron concretions/staining)

Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)

Banded Agate (Polished Slice) (Chalcedony (cryptocrystalline Quartz), SiO2) — mineral

Banded Agate (Polished Slice)

Chalcedony (cryptocrystalline Quartz), SiO2

Serpentinite (Serpentinite (composed primarily of minerals in the Serpentine group)) — metamorphic

Serpentinite

Serpentinite (composed primarily of minerals in the Serpentine group)

Banded Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Banded Gneiss

Gneiss (High-grade metamorphic rock)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Sandstone (likely Quartzose Sandstone) (Arenite (SiO2 based)) — sedimentary

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 based)

Gold-Bearing Quartz (Silicon Dioxide with Native Gold (SiO2 + Au)) — mineral

Gold-Bearing Quartz

Silicon Dioxide with Native Gold (SiO2 + Au)

Sandstone (Red Sandstone) (Arenite (SiO2 based with Fe2O3 staining)) — sedimentary

Sandstone (Red Sandstone)

Arenite (SiO2 based with Fe2O3 staining)

Quartz Geode (Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell) — sedimentary

Quartz Geode

Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell

Basalt with Quartz/Calcite Vein (Amygdaloidal Basalt (matrix) with Mineral Vein filling) — igneous

Basalt with Quartz/Calcite Vein

Amygdaloidal Basalt (matrix) with Mineral Vein filling

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Granite (Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Grey and White Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Grey and White Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint Pebbles) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Quartz-rich) (Clastic sedimentary rock (SiO2 primary)) — sedimentary

Sandstone (Quartz-rich)

Clastic sedimentary rock (SiO2 primary)

Jasper (Petrified Wood variant) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Jasper (Petrified Wood variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Basalt with Quartz Veining (Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins) — igneous

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Quartz Vein on Matrix (Silicon Dioxide (SiO2)) — mineral

Quartz Vein on Matrix

Silicon Dioxide (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Amber (Black) (Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)) — Mineraloid

Amber (Black)

Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)

Ironstone Concretion (Limonite/Hematite Nodules) (Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)) — sedimentary

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)

Chert (Quartz Variety) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Quartz Variety)

Microcrystalline Silica (SiO2)

Granodiorite (Granodiorite (phaneritic intrusive igneous rock)) — igneous

Granodiorite

Granodiorite (phaneritic intrusive igneous rock)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Brown Sandstone (Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)) — sedimentary

Brown Sandstone

Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)

Sandy Ironstone (Ferruginous Sandstone) — sedimentary

Sandy Ironstone

Ferruginous Sandstone

Amber (specifically Cherry Amber) (Succinite (with the chemical formula C10H16O)) — Organic Gemstone (not a mineral)

Amber (specifically Cherry Amber)

Succinite (with the chemical formula C10H16O)

Organic Gemstone (not a mineral)

Amber (Succinite (fossilized tree resin)) — mineraloid

Amber

Succinite (fossilized tree resin)

Baltic Amber (Succinite (Polmerized conifer resin)) — mineraloid

Baltic Amber

Succinite (Polmerized conifer resin)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Quartz Geode (Silicon Dioxide (SiO2) in Host Rock) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Wishing Stone (Basalt/Greywacke with Quartz Vein) (Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion) — igneous/sedimentary

Wishing Stone (Basalt/Greywacke with Quartz Vein)

Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion

igneous/sedimentary

Moss Agate (Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides

Sandstone with Concretions / Liesegang Rings (Arenite with iron oxide banding) — sedimentary

Sandstone with Concretions / Liesegang Rings

Arenite with iron oxide banding

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

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)