Limestone
Calcium Carbonate (CaCO3)
Category
Browse sedimentary (fossilized organic remain) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based clastic rock)
Chert Nodule
Microcrystalline Quartz (SiO2)
Nuummite
Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)
Sandstone (Ferruginous)
Arenite (Fe2O3 dominant staining)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Red Sandstone
Arenite (high iron oxide content)
Red Sandstone
Arenite (Ferruginous Sandstone)
Red Sandstone
Arenite (predominantly SiO2 with Fe2O3)
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
Fancy Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Sandstone (Grooved/Weathered)
Arenite (composed primarily of Quartz and Lithic fragments)
Red Jasper (Mahogany Obsidian variant similarity)
Silicon Dioxide (SiO2) with iron oxide inclusions
Brown Jasper
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Banded Sandstone
Arenite (composed primarily of Quartz: SiO2)
Jasper
Silicon dioxide (SiO2)
Red Sandstone
Arenite (with Iron Oxide cement)
Metaconglomerate
Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline Silica (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Sandstone with Liesegang Rings
Arenite with secondary Iron oxide (Limonite/Goethite) precipitation
Quartz Crystal
Quartz (SiO₂)
Quartz
Silicon Dioxide (SiO2)
Pyrite
Pyrite (FeS2)
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)
Sandstone (Ferruginous)
Arenite (with Iron Oxides)
Sandstone
Arenite (SiO2 + various cementing minerals)
Sandstone (Ferruginous)
Sandstone (Clastic sedimentary rock, predominantly SiO2 with Fe2O3 cement)
Fossiliferous Limestone (Bivalve Fossil)
Calcium Carbonate (CaCO3) with Bivalvia fossil
Sandstone (with Manganese staining)
Arenite (composed primarily of SiO2)
Limestone Pebble
Calcium Carbonate (CaCO3)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
Quartzite River Stone
Quartzite (primarily SiO2)
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
Hematite / Goethite (Iron Ore)
Iron Oxide (Fe2O3 / FeO(OH))