Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Mineral (Sedimentary context)
Category
Mineral (Sedimentary Context)
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
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Unidentified small brown rock
Undetermined; image does not show enough detail for reliable identification
sedimentary
Unidentifiable embedded dark fragment
Indeterminate; possibly a dark silicate mineral or lithic inclusion
mineral
Jasper / Chert (Red)
Cryptocrystalline quartz (SiO2)
Sedimentary / Mineral
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock pebble
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Weathered stone nodule or concretion
Unidentified lithic concretion; composition cannot be determined from the image
sedimentary
Quartz-rich rock fragment
Unidentified quartz–feldspar-rich rock; exact lithology cannot be determined from the image
igneous
Pyrite and Sunstone
Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)
mineral
Chert (Flint) Artifact
Silicon Dioxide (SiO2)
sedimentary
Sandstone
Arenite (primarily Quartz Sandstone)
sedimentary
Glauconitic Sandstone (or Greenstone)
Glauconitic Sandstone with Quartz
sedimentary
Fossilized bone fragment
Fossil bone, composed chiefly of carbonate-fluorapatite (bioapatite)
fossil
Goethite pseudomorph after Pyrite
Goethite (FeO(OH)) pseudomorph after Pyrite (FeS2)
mineral
Pyrite in Matrix (likely Quartz or Schist matrix)
Iron Sulfide (FeS2)
mineral
Fossil bivalve shell
Fossilized or partially mineralized bivalve; exact genus cannot be determined from the image
fossil
Sandstone or Quartzite with algae
Unknown specific, largely SiO2 with biological growth
sedimentary or metamorphic
Unidentified gray stone
Likely quartz-rich stone; exact identification is not possible from the image
mineral
Chert or chalcedony nodule
Microcrystalline quartz (SiO₂), possibly weathered chert
mineral
Chert Nodules in Limestone
Microcrystalline Quartz (SiO2) in Carbonate Matrix
sedimentary
Note on Image Identification: Textile
N/A (Anthropogenic material)
not a rock
Weathered pale-blue rock fragment
Unidentified; the image does not show enough detail for a reliable geological identification
sedimentary
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
sedimentary
Hematite (Tumbled)
Iron(III) oxide (Fe2O3)
mineral
Coprolite
Fossilized Feces
fossil
Fossilized bone or tooth fragment
Mineralized vertebrate bone; exact taxon indeterminate from image
fossil
Fossilized shell or small fossil fragment
Indeterminate fossil; possibly a partial gastropod or bivalve, mineralized with calcite
fossil
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
sedimentary
Ironstone Concretion (Moqui Marble type)
Ironstone Concretion (Fe2O3 with SiO2 core)
sedimentary
Black Jasper
Silicon dioxide (SiO2) with carbon/mineral inclusions
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Chert / Flint Handaxe
Cryptocrystalline Quartz (SiO2)
sedimentary
Small pale stone, possibly quartz or limestone
Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)
mineral
Chert / Flint (Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Cream Variety)
Microcrystalline silica (SiO2)
sedimentary
Nutting Stone / Cupstone (Sandstone or Quartzite)
Sedimentary rock with anthropogenic modification (cupule)
sedimentary
Ferruginous Sandstone
Ferruginous Sandstone (Quartz Arenite with Iron Oxide cement)
sedimentary
Chert / Flint Tool
Cryptocrystalline quartz (SiO2)
sedimentary
Chert / Flint Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Polished rose quartz
Quartz (silicon dioxide, SiO₂), rose-colored variety
mineral
Chert (Flint variety)
Microcrystalline context of Quartz (SiO2)
sedimentary
Tumbled limestone or marble
Calcite-rich carbonate rock; likely limestone (CaCO₃), possibly marble
metamorphic