Jasper
Silicon dioxide (SiO2)
Sedimentary / Mineral
Category
Sedimentary (With Some Aspects Of Mineral Replacement)
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
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Fossilized Bone
Permineralized Vertebrate Bone
fossil
Fossilized Trilobite or Mollusk Fragment
Phylum Arthropoda / Mollusca fossil in sedimentary matrix
fossil
Fossilized Bone Fragment
Permineralized Skeletal Element (Likely Vertebrate)
sedimentary
Bivalve Fossil (Clam)
Class Bivalvia (Mollusca)
fossil
Quartz-rich rock, likely chert or chalcedony
Microcrystalline silica (SiO₂), possibly quartz/chalcedony
mineral
Fossil oyster shell
Ostrea or Exogyra sp. (identification uncertain)
fossil
Polished orbicular jasper (likely ocean jasper)
Silicified microcrystalline quartz/chalcedony; mainly SiO₂ with iron-oxide inclusions
mineral
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Gastropod Fossil (Snail Stone or Steinkern)
Class Gastropoda (Calcium Carbonate - CaCO3 / Silica - SiO2 replacing original shell)
sedimentary
Fossil coral fragment
Likely scleractinian coral; calcium carbonate, predominantly aragonite or recrystallized calcite (CaCO₃)
fossil
Tiger's Eye
Silicon dioxide (Quartz pseudomorph after crocidolite), SiO2
gemstone
Possible fossilized bone fragment
Indeterminate mineralized bone; taxon and age cannot be determined from the photo
fossil
Sandstone (likely Siltstone)
Arenite or Siltstone (high SiO2 content)
sedimentary
Red Jasper Concretion
Cryptocrystalline Quartz (SiO2)
sedimentary
Grey Chalcedony (Tumbled)
Chalcedony (SiO2)
mineral
Flint with Chalk Cortex
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Chert (Flint nodules in Limestone)
Silicon dioxide (SiO2)
sedimentary
Chert (Chalcedony / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz / Chert
sedimentary
Chert (Jasper / Flint variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Flint
SiO2 (Cryptocrystalline Quartz)
sedimentary
Chert (Chalcedony/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Fossil ammonite
Ammonite (subclass Ammonoidea; exact species not identifiable from the image)
fossil
Ammonite Fossil
Ammonoidea
fossil
Magnetite (Octahedral Crystal)
Magnetite (Fe3O4)
mineral
Polished/tumbled brecciated jasper (likely rainforest or ocean jasper)
Microcrystalline quartz (SiO₂), commonly mixed with chalcedony, iron oxides, and other silicates
mineral
Fossilized shell or bone fragment
Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone
fossil
Possible fossilized bone or tooth fragment
Indeterminate fossilized vertebrate material; mineralized hydroxyapatite replaced or coated by silica/carbonate
fossil
Quartz Vein in Hematitic Siltstone
Hydrothermal Quartz (SiO2) in Ferriferous Matrix
metamorphic
Magnetite or Magnetic Iron Ore
Magnetite (Fe3O4)
mineral
Ammonite fossil
Ammonoidea; likely a Jurassic or Cretaceous ammonite
fossil
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Ironstone concretion (likely limonite/goethite-rich)
Iron-oxide-cemented sediment, commonly goethite (FeO(OH)) and/or limonite
sedimentary
Jasper
Jasper (Silicate mineral, SiO2)
sedimentary
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Dinosaur Fossil (Skull)
Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)
sedimentary
Black Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary