Siltstone with Fossil Cast
Sedimentary Rock (Siltstone / Fine-grained Sandstone)
sedimentary
Category
Organic Mineraloid And Mineral
Browse organic mineraloid and mineral specimens identified by the Rock Identifier community.
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Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
sedimentary
Chert Nodule / Ironstone Concretion
Microcrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
sedimentary
Chert (with Epidote/Quartz veining)
Cryptocrystalline silica (SiO2) with Epidote/Quartz inclusions
sedimentary
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
mineral and organic gemstone
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
sedimentary
Fossil Shark Tooth
Chondrichthyes (Class)
fossil
Fossilized Coprolite
Coprolite (fossilized feces)
sedimentary
Mammoth or Mastodon Tooth Fragment
Mammuthus / Mammut molar fragment
fossil
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
sedimentary
Petrified Wood
Silicified Wood (mainly Quartz / SiO2)
fossil
Petrified Wood Fragment
Silicified Wood (SiO2)
fossil
Amber
Succinite (C10H16O)
mineral
Amber and Tumbled Stones
Fossilized Tree Resin (Succinite)
fossil
Amber
Succinite (Resinite)
fossil
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
sedimentary
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Fossilized coral (likely honeycomb or branching coral)
Fossil coral; probable Scleractinia or Tabulata, composition mainly microcrystalline CaCO₃
fossil
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
mineraloid (synthetic)
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
sedimentary
Fossil Shark Tooth (Sand Tiger or Mackerel Shark)
Carcharias sp. or Otodus sp. replaced by Hydroxylapatite/Calcium Carbonate
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Silicon Dioxide, SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite (Fool's Gold) in Matrix
Iron Sulfide (FeS2)
mineral
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
mineral
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
mineral
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
sedimentary
Ironstone Concretion
Ironstone (primarily Siderite or Limonite)
sedimentary
Black Shale
Argillaceous Chert/Shale
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
sedimentary
Fossil mammalian skull
Fossilized vertebrate bone; exact taxon cannot be determined from the image
fossil
Petrified Wood
Silicified wood (SiO2)
fossil
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
sedimentary
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary