Black Opal (Triplet)
Hydrated Silica (SiO2·nH2O)
mineral
Category
Sedimentary (Anthropogenic)
Browse sedimentary (anthropogenic) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Anthropogenic) in the encyclopedia
View all →
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Limestone
Calcite (CaCO3)
sedimentary
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Anthropogenic (Man-made product subject to geological processes)
Ferruginous Siltstone
Siltstone with Magnetite/Hematite bands
sedimentary
Sandstone (Quartzite-rich Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (Pebble)
Arenite
sedimentary
Red Jasper (or Banded Jasper)
Silicon Dioxide (SiO2 with Hematite impurities)
mineral
Sandstone Pebble
Arenite
sedimentary
Common Opal / Chert
Hydrated silica (SiO2·nH2O) or Microcrystalline Quartz (SiO2)
mineral
Glauconitic Sandstone
Glauconitic Sandstone (Quartz with Glauconite)
sedimentary
Fossil Sponge / Horn Coral / Crinoid Stem
Phylum Porifera or Cnidaria fossilized in calcium carbonate / silica
fossil
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (likely Graywacke or Lithic Arenite)
Clastic sedimentary rock predominantly composed of silicate grains
sedimentary
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Red Sandstone
Arenite (SiO2 with Fe2O3)
sedimentary
Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
sedimentary
Quartzite Conglomerate
Conglomerate (SiO2 rich)
sedimentary
Red Jasper (or Agate/Jasper mixture)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Chert (specifically Gray/Blue-Gray Chert)
Chert (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Magnetite / Ironstone
Magnetite (Fe3O4)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Red Jasper (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
sedimentary
Red Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Brachiopod Fossil in Matrix
Phylum Brachiopoda
fossil
Quartz Geode
Silicon Dioxide (SiO2) within a sedimentary or igneous host
sedimentary
Banded Iron Formation
Banded Iron Formation (BIF)
sedimentary
Glauconitic Sandstone
Glauconitic sandstone ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Sandstone or Siltstone
Arenite or Siltstone
sedimentary
Banded Sedimentary Rock
Stratified Siliciclastic / Arenite or Siltstone with Mineral Bands
sedimentary
Weathered Sedimentary Rock with Liesegang Rings
Sandstone or Siltstone with Iron Oxide Banding
sedimentary
Sandstone (Sedimentary Rock)
Arenite (SiO2 based)
sedimentary
Chalk (Sedimentary Limestone)
Calcite (CaCO3)
sedimentary
Sedimentary River Rock
Siliciclastic Sedimentary Rock (Quartzite or Sandstone pebble)
sedimentary
Banded Sedimentary Rock (Siltstone/Mudstone with concretion)
Siltstone with Ferruginous Banding
sedimentary
River Stone (Sedimentary Sandstone/Quartzite)
Arenite/Quartzite transition specimen
sedimentary