Ambergris
Ambergris (Coprolite-adjacent organic substance)
Organic (Geological interest)
Category
Organic (Geological Interest)
Browse organic (geological interest) specimens identified by the Rock Identifier community.
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
mineral
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
fossil
Chert (Nodule)
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Unknown Rock Specimen
igneous
Banded Sedimentary Rock (Siltstone/Mudstone with concretion)
Siltstone with Ferruginous Banding
sedimentary
Chert with Crinoid Fossil Impression
Microcrystalline Quartz (SiO2) with Crinoidea fossil impression
sedimentary
Hardpan Nodule / Ferruginous Sandstone
Ferruginous Sandstone (Fe-cemented sediment)
sedimentary
Chert (Jasper-like Silicate)
Microcrystalline quartz (SiO2)
sedimentary
Yellow Chert
Sedimentary cryptocrystalline quartz (SiO2)
sedimentary
Ironstone Concretion
Siderite or Goethite Concretion
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Tonsil Stone (Tonsillolith)
Calcium phosphate / Calcium carbonate biomineral
mineral
Basalt with Quartz Vein
Extrusive Igneous Rock / Volcanic Rock
igneous
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Gossanous Sandstone (likely Terrestrial)
Arenite with Iron-Oxide inclusions
sedimentary
Fossiliferous Sandstone / Quartzite Pebble
Sedimentary rock with skeletal fragments (e.g., Paleozoic crinoid/brachiopod fossils)
fossil
Ferruginous Sandstone (Gozzan)
Iron-rich clastic sedimentary rock with Limonite/Goethite
sedimentary
Sandstone with Iron Oxide Concretion
Arenite with Hematite/Goethite Concretion
sedimentary
Fossiliferous Limestone
Limestone with embedded fossil cross-section
sedimentary
Coprolite
Fossilized Feces
fossil
Omarolluk (Omar)
Siliceous greywacke with carbonate concretions
sedimentary
Ironstone Concretion
Ironstone (Limonite/Goethite Concretion)
sedimentary
Painted River Rock (likely Quartzite or Granite)
Quartzite or Granitic Gneiss (painted)
metamorphic
Weathered rock fragment
Undetermined; possibly a coarse-grained granitoid
igneous
Chert (specifically Cryptocrystalline Quartz)
Silicon dioxide (SiO2)
sedimentary
Sandstone Concretion
Ferruginous Sandstone Concretion
sedimentary
Milky quartz vein in dark host rock
Quartz (SiO₂), likely occurring as a vein within a fine-grained host rock
mineral
Chert Concretion
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary
Small gray rock fragment
Unidentified rock; the image lacks enough detail for reliable mineral identification
igneous
Concretion
Calcareous or ferruginous concretion
sedimentary
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
sedimentary
Banded Sedimentary Rock
Sedimentary rock with Liesegang banding
sedimentary
Concrete Rubble with Aggregate
Hardened Portland Cement Paste with Coarse Aggregate
Anthropogenic (Man-made)
Concretion
Septarian or Siderite Concretion
sedimentary
Chert (Septarian Nodules-like)
Silicon dioxide (SiO2)
sedimentary
Chert (within Limestone)
Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) matrix
sedimentary