Sandstone Pebble (River Rock)
Sandstone (Quartz-rich sedimentary rock with iron oxide staining)
sedimentary
Category
Organic Materia (Not A Rock Or Mineral)
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
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Chert (Jasper-like Silicate)
Microcrystalline Quartz (SiO2)
sedimentary
Chert Concretion
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
sedimentary
Chert Concretion (Flint)
Silicon Dioxide (SiO2)
sedimentary
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
mineral
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
sedimentary
Fossilized Coral (Petrified Coral)
Lithostrotionella (example genus) / Scleractinia
fossil
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Petrified Wood
Silicified wood (Quartz replacement, SiO2)
fossil
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in sedimentary host rock
sedimentary
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
mineral
Fossiliferous Sandstone / Fossil Fragment
Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material
fossil
Yellow Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Ironstone Concretion (Boxwork)
Siderite-Limonite Concretion (FeO(OH)·nH2O)
sedimentary
Sandstone (Red / Iron-stained)
Sandstone (composed predominantly of SiO2 with Fe2O3 cement)
sedimentary
Chert (Jaspery variety)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Coral
Cnidaria fossil / Calcite-replaced coral
fossil
River-worn Chert
Microcrystalline Quartz (SiO2)
sedimentary
Ironstone Concretion / Goethite-Hematite Geode
Goethite / Hematite Concretion (Fe3O4 / FeO(OH) / Fe2O3)
sedimentary
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
sedimentary
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
sedimentary
Amber
Succinite (formula varies, primarily C10H16O)
Mineraloid (Organic)
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Fossilized Shark Tooth
Chondrichthyes tooth
fossil
Fossiliferous Limestone containing a Brachiopod or Mollusk Impression
Biogenic Sedimentary Rock / Fossiliferous Limestone
sedimentary
Fossilized Coral
Rugosa / Scleractinia (Agatized or Calcitized Coral)
fossil
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Raw Amber / Resin Mineral
Succinite (Fossilized Tree Resin)
gemstone
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
sedimentary
Tufa (Limestone)
Calcareous Tufa (CaCO3)
sedimentary
Banded Chert / Sandstone Pebble
Microcrystalline Quartz (SiO2) / Silicified Sandstone
sedimentary
Chert (Common Opal/Agatized Rock)
Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Banded Chert (likely Flint or Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
sedimentary
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
sedimentary
Ammonite Fossil (Small Pyritized or Calcitized Internal Mold)
Ammonoidea
sedimentary