Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
sedimentary
Category
Organic Materia (Not A Rock Or Mineral)
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Organic Materia (Not A Rock Or Mineral) in the encyclopedia
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White limestone or chalky carbonate rock
Calcite-rich limestone; possibly chalk (CaCO₃)
sedimentary
Shale
Shale (Fine-grained clastic sedimentary rock)
sedimentary
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
sedimentary
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
sedimentary
Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
sedimentary
Petrified Wood
Silicified wood (SiO2)
fossil
Dendritic jasper/chalcedony
Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites
mineral
Fossilized Brachiopod
Brachiopoda (Phylum)
fossil
Jasper
Silicon dioxide (SiO2)
sedimentary
Fossilized Shark Tooth
Chondrichthyes (class)
fossil
Asphalt aggregate
Human-made bituminous asphalt containing crushed silicate rock aggregate
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
mineral
Fossilized Nut / Coprolite / Concretion
Trace Fossil / Permineralized Plant Material
fossil
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Fossilized Bone
Petrified Bone (Fluorapatite / Calcium Phosphate replacement)
fossil
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Quartz vein in host rock
Quartz (SiO₂), likely in a weathered carbonate or sedimentary matrix
mineral
Seashell Fossil
Gastropoda fossil
fossil
Pyrite in Shale
Iron Disulfide (FeS2)
mineral
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
mineral
Petrified Bone (Fossil Bone)
Per mineralization fossil bone (varies by organism, predominantly replacement by SiO2 - Quartz/Chalcedony)
fossil
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
sedimentary
Herkimer Diamond
Quartz (Silica - SiO2)
mineral
Amber
Fossilized Tree Resin
gemstone
Starfish Fossil
Asteroidea fossil
fossil
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Sandstone)
sedimentary
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Shale
Fissile Mudstone (Shale)
sedimentary
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
sedimentary
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
fossil
Fossiliferous limestone
Bioclastic carbonate rock; predominantly calcite (CaCO₃)
sedimentary
Fossiliferous Sandstone / Mudstone
Sedimentary Rock (Clastic with Fossiliferous Inclusions)
sedimentary
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
fossil
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Shark Tooth Fossil
Chondrichthyes (class) fossilized tooth
fossil
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary