Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Category
Organic Specimen (Fossil)
Browse organic specimen (fossil) specimens identified by the Rock Identifier community.
Sandstone
Arenite (SiO2 based with mineral cement)
sedimentary
Fossilized Solitary Rugose Coral (Horn Coral)
Order: Rugosa (e.g., Grewingkia or Heliophyllum); composed of Calcite (CaCO3) or Silica (SiO2)
sedimentary
Fossilized Shark Tooth
Carcharodon (Galeocerdo sp. or Lamniform)
mineral
Chert (specifically Yellow Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Red Sandstone
Arenite with Hematite cementation
sedimentary
Flesh-toned Siltstone
Siltstone (composed of microscopic Quartz and Feldspar grains)
sedimentary
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Limestone
Calcium carbonate (CaCO3)
sedimentary
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)
sedimentary
Chert (Grey-Green Var.)
Silicon Dioxide (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
mineral (silicate-replaced organic material)
Chert (Iron-stained River Cobble)
Microcrystalline Quartz (SiO2)
sedimentary
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Mineral
Shale
Fissile Mudrock (Clay-rich Sedimentary Rock)
sedimentary
Pyrite
Pyrite (Iron Disulfide), FeS2
Mineral
Spinosaurus Tooth
Spinosaurus aegyptiacus (fossilized in Hydroxyapatite)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
sedimentary
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite/Quartz Arenite
sedimentary
Orthoceras Fossil in Limestone
Orthoceras regulare
sedimentary
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Limestone (specifically Fossiliferous Limestone)
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Chert (Iron-stained)
Chert (primarily Microcrystalline Quartz, SiO2)
sedimentary
Bivalve Fossil (Clam/Mollusk)
Class: Bivalvia (Order: Veneroida), Calcium Carbonate (CaCO3)
sedimentary
Iridescent Ammonite Fossil
Ammonoidea (subclass); Composition: Aragonite (Calcium Carbonate, CaCO3) often replaced by Calcite or Pyrite
sedimentary
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Crinoid Stem Fossil (in matrix)
Crinoid (Class Crinoidea)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Fe2O3 staining)
sedimentary
Pyrite
Pyrite (Iron sulfide, FeS₂)
mineral
Sandstone (Quartz-rich)
Arenite (SiO2 based)
sedimentary
Chert (Green variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Pyrite Sun (Pyrite Dollar)
Iron Disulfide (FeS2)
mineral
Limestone
Calcareous Sedimentary Rock (CaCO3)
sedimentary
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Orthoceras Fossil Limestone
Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)
sedimentary