Rock Identifier

Category

Sedimentary (Biogenic)

Browse sedimentary (biogenic) specimens identified by the Rock Identifier community.

Limonite (Iron-rich Siltstone / Sandstone base) (Hydrous ferric oxide mixture (FeO(OH)·nH2O)) — sedimentary

Limonite (Iron-rich Siltstone / Sandstone base)

Hydrous ferric oxide mixture (FeO(OH)·nH2O)

Sandstone (Red/Brown Variety) (Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)) — sedimentary

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Ammonite Fossil (Ammonoidea (subclass)) — sedimentary

Ammonite Fossil

Ammonoidea (subclass)

Ironstone (likely siderite or goethite-rich siltstone) (Ferruginous Siltstone) — sedimentary

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert Nodule (Microcrystalline Silica (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Silica (SiO2)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Fossiliferous Limestone with Brachiopod shell (Calcium carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone with Brachiopod shell

Calcium carbonate (CaCO3)

Conglomerate (Conglomerate (Rock composed predominantly of rounded clasts > 2mm)) — sedimentary

Conglomerate

Conglomerate (Rock composed predominantly of rounded clasts > 2mm)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (and/or Flint) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (with differential weathering) (Arenite / Quartz Sandstone (SiO2)) — sedimentary

Sandstone (with differential weathering)

Arenite / Quartz Sandstone (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Chert (specifically Flint or Gray Chert) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (SiO2)

Sandstone (specifically an Iron-Concretion) (Arenite with Iron Oxide (Limonite/Goethite) cementation) — sedimentary

Sandstone (specifically an Iron-Concretion)

Arenite with Iron Oxide (Limonite/Goethite) cementation

Limestone with Weathering Rind (Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone) — sedimentary

Limestone with Weathering Rind

Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Pyrite with Limonite/Goethite Alteration (Pseudomorph) (Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)) — mineral

Pyrite with Limonite/Goethite Alteration (Pseudomorph)

Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)

Yellow Ochre / Limonite (Limonite (FeO(OH)·nH2O)) — Mineral

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Quartz (Milky or Cloudy Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Cloudy Quartz)

Silicon Dioxide (SiO2)

Precious Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Precious Opal

Hydrated Silica (SiO2·nH2O)

Quartzite (or Iron-Stained Quartz Pebble) (Silicon Dioxide (SiO2) with Ferric Oxide inclusions) — metamorphic

Quartzite (or Iron-Stained Quartz Pebble)

Silicon Dioxide (SiO2) with Ferric Oxide inclusions

Goethite (Iron Ore) (Goethite (FeO(OH))) — mineral

Goethite (Iron Ore)

Goethite (FeO(OH))

Limonite (Iron Ore) (Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)

Petrified Wood (Silicified wood (primarily Quartz/Chalcedony, SiO2)) — metamorphic

Petrified Wood

Silicified wood (primarily Quartz/Chalcedony, SiO2)

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

Red Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Quartz Geode (Citrine or Iron-stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz Geode (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Chalcedony (Common Opal/Chert variety) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

White Marble (Recrystallized Calcite (CaCO3)) — metamorphic

White Marble

Recrystallized Calcite (CaCO3)

Chert (Agatized) (Silicon dioxide (SiO2)) — sedimentary

Chert (Agatized)

Silicon dioxide (SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Carnelian (Carnelian (SiO2 variant)) — mineral

Carnelian

Carnelian (SiO2 variant)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Gold (Native Gold (Au)) — mineral

Gold

Native Gold (Au)