Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Category
Browse sedimentary (anthropogenic) specimens identified by the Rock Identifier community.
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Bivalve Seashell Fossil
Class Bivalvia
Rounded quartz-rich sandstone cobble
Quartz arenite (sandstone), likely iron-stained
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Red Jasper (or Agate/Jasper mixture)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Red Jasper (or Banded Jasper)
Silicon Dioxide (SiO2 with Hematite impurities)
Banded sedimentary rock (likely sandstone or siltstone)
Layered siliciclastic sedimentary rock; exact identification is not possible from the image alone
Fossiliferous Limestone with Brachiopod
Phylum Brachiopoda in calcitic matrix
Lepidodendron Fossil in Sandstone
Lepidodendron (Lycophytina, Lepidodendrales)
Sandstone / Weathered Quartzite
Sandstone (Quartz Arenite)
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
Quartz-veined Sandstone Pebble
Quartzite-veined Arenite
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
Banded gneiss
Quartz–feldspar gneiss, possibly biotite-bearing; exact identification requires testing
Banded gneiss
Gneiss, commonly quartz–feldspar–mica gneiss
Coal
Bituminous Coal / Anthracite
Ironstone concretion
Iron-oxide-cemented sedimentary concretion, commonly hematite/goethite with quartz or clay
Banded sandstone pebble
Lithic or quartz-rich sandstone; exact composition requires testing
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Ironstone Pebble
Sedimentary Ironstone (Hematite/Limonite-bearing)
Sandstone (with Iron Oxide)
Quartz Arenite / Ferruginous Sandstone (SiO2 with Fe2O3)
Limonite with Trace Fossils
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Coquina / Shelly Sandstone
Calcareous Sandstone / Coquina
Banded gneiss
Foliated gneiss, likely quartz–feldspar–mica gneiss
Milky quartz crystal cluster
Quartz (silicon dioxide, SiO₂)
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Sandstone Pebble
Arenite
Sandstone (Pebble)
Arenite
Jasper
SiO2
Sandstone
Sedimentary Rock (Quartz Sandstone)
Sandstone Pebble
Quartz Sandstone
Red Sandstone
Quartz Arenite (iron-stained)
Limestone
Calcite-rich carbonate rock (primarily CaCO₃)
Chert (specifically Gray/Blue-Gray Chert)
Chert (SiO2)
Moqui Marble (Concretion)
Iron Oxide Concretion (Hematite-cemented Sandstone)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Magnetite / Ironstone
Magnetite (Fe3O4)
Pyrite-bearing sulfide specimen
Pyrite (FeS₂), possibly mixed with chalcopyrite or other iron sulfides
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)