Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
sedimentary
Category
Sedimentary Rock (Metamorphosed)
Browse sedimentary rock (metamorphosed) specimens identified by the Rock Identifier community.
Sandstone
Arenite
sedimentary
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
sedimentary
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
sedimentary
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
sedimentary
Fossiliferous Shale Matrix
Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments
sedimentary
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Sedimentary
General Rock and Mineral Collection (Center: Angelite / Blue Anhydrite)
Anhydrite (Calcium Sulfate, CaSO4)
Mineral
Gneiss (High-grade Metamorphic Rock)
Gneiss (Metamorphic silicate rock)
metamorphic
Yellow Ochre / Limonite
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Greywacke with Quartz Vein
Matrix: Impure Sandstone (SiO2 + varied clasts), Veins: Quartz (SiO2)
sedimentary
Red Sandstone
Arenite (with Iron Oxide)
sedimentary
Sandstone (Picture Sandstone)
Sandstone (primarily Quartz with Iron Oxide impurities)
sedimentary
Ammonite Fossil in Limestone Matrix
Ammonoidea (subclass) in Calcium Carbonate (CaCO3)
sedimentary
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Pyrite (on host rock)
Iron Sulfide (FeS2)
mineral
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
mineral
Graphite Schist
C (Carbonaceous Schist)
metamorphic
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
sedimentary
Coquina
Bioclastic Limestone
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (specifically Agate/Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Red Jasper
Red Jasper (SiO2 with Fe2O3 impurities)
sedimentary
Concretion or Geode (unbroken)
Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.
Sedimentary rock (specifically a concretion or possibly a geode)
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Chalcedony (Botryoidal/Agate nodule)
Microcrystalline Quartz (SiO2)
mineral
Banded Agate (with Quartz Geode Center)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Agate
Silicon Dioxide (SiO2)
mineral
Yellow Quartz (Chalcedony or Agate)
Silicon Dioxide (SiO2)
mineral
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
mineral
Crazy Lace Agate
Silicon Dioxide (SiO2) with iron and aluminum inclusions
sedimentary mineral
Dyed Blue Agate
Silicon Dioxide (SiO2)
Mineral
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Clear Quartz
Silicon Dioxide (SiO2) / Rock Crystal
mineral
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
sedimentary
Quartz Pebble (Geode-like)
Silicon Dioxide (SiO2)
Mineral
Jasper (Chert)
Silicon Dioxide (SiO2)
sedimentary
Dalmatian Stone (often called Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)
igneous
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic