Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Category
Organic (Anthropogenic)
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
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Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
mineral
Calcareous Tufa / Limestone Fragment
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
sedimentary
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
mineral
Amber / Copal
Succinite (fossilized resin)
mineraloid
Fossilized Sand Tiger Shark Tooth
Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)
sedimentary (fossil)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
mineral
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Favosites Fossil (Honeycomb Coral)
Favosites (Extinct genus of Tabulate Coral)
sedimentary
Glauconitic Sandstone
Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2
sedimentary
Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression)
Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)
sedimentary
Graphite-rich schist (likely graphite ore)
Graphite-bearing schist; predominantly graphitic carbon (C) with mica, quartz, and possible feldspar
metamorphic
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth
Chondrichthyes (class) fossilized tooth
fossil
Fossilized Bone / Dinosaur Fossil
Fossilized vertebrate bone (permineralized)
fossil
Shark Tooth Fossil
Carcharodon / Otodus fossilized tooth (Calcium Phosphate / Hydroxyapatite)
fossil
Fossilized Shark Tooth
Chondrichthyes (Class)
fossil
Fossilized Bivalve Shell
Bivalvia (Phylum Mollusca)
fossil
Fossilized Bivalve Shell (Fossilized Clam)
Bivalvia (class) / CaCO3 (Calcium Carbonate)
fossil
Banded Chert / Agate
Silicon Dioxide (SiO2)
sedimentary
Calcareous Tufa (or Travertine)
Calcium Carbonate (CaCO3)
sedimentary
Banded Chert (likely Flint or Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Grey Chert River Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Sand Tiger Shark Tooth
Carcharias taurus (fossilized)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Green Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Chert (Flint) Artifact
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Trace Fossil (Lichenandites or Rhynie Chert Chert with Microfossils)
Trace fossil in microcrystalline quartz (SiO2)
fossil
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary