Chert / Pink Flint
Cryptocrystalline Quartz (SiO2)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Chert / Pink Flint
Cryptocrystalline Quartz (SiO2)
Fossilized Bivalve Shell
Bivalvia (Phylum Mollusca)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Fossilized Bone / Dinosaur Fossil
Fossilized vertebrate bone (permineralized)
Petrified Wood
Silicified Wood (SiO2)
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Veined Limestone
Sedimentary Calcite-Veined Rock (CaCO3)
Granite, possibly granodiorite
Coarse-grained felsic plutonic rock; chiefly quartz (SiO₂), potassium feldspar and plagioclase feldspar, with biotite and/or hornblende
Chert (River Siltstone/Quartzite type)
Microcrystalline Quartz (SiO2)
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
Crushed Limestone
Sedimentary Calcite/Dolomite Rock (CaCO3)
Amber (fossilized tree resin)
Succinite; organic resin composed mainly of polymerized terpenoids
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
Chert (Smooth River Stone)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Green Moss Agate
Silicon Dioxide (SiO2) with Mineral Inclusions
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Precious Red Coral
Corallium rubrum / Corallium japonicum
Bituminous Coal
Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)
Chert (and Limestone) River Cobble
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Polished agate (likely plume or moss agate)
Chalcedony, microcrystalline quartz (SiO₂), with iron-oxide and possible chlorite inclusions
Flint or chert, possibly a knapped stone tool
Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities
Precious Coral
Corallium rubrum
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Ironstone Concretion / Goethite-Hematite Geode
Goethite / Hematite Concretion (Fe3O4 / FeO(OH) / Fe2O3)
Fossilized Wood / Petrified Wood
Petrified Wood (Silicified Flora)
Flint (Chert)
Silicon Dioxide (SiO2)
Chert (Green River Chert)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Lapis Lazuli
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Fossilized Dinosaur Bone
Perineralized Bone (Fluorapatite/Quartz replacement)
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Shale (possibly Carbonaceous or Oil Shale)
Laminated Mudstone (primarily clay minerals and quartz)