Gneiss
Gneiss
Category
Browse sedimentary rock specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Banded Gneiss
Banded Orthogneiss or Paragneiss (Quartz-Feldspathic Gneiss)
Petrified Wood
Silicified Wood (SiO2)
Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Sandstone Cobble
Arenite (predominantly Quartz Sandstone)
Garnet Schist
Almandine Garnet in Schist (X3Al2(SiO4)3)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Crushed Limestone
Sedimentary Calcium Carbonate (CaCO3)
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (SiO2 primarily)
Clear Quartz / Rock Crystal
Silicon Dioxide (SiO2)
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
Chalcedony (Agate/Quartz)
Silicon Dioxide (SiO2)
Quartz (Smoky/Clear variety)
Silicon Dioxide (SiO2)
Ferruginous Sandstone Pebble
Arenite with Iron Oxide matrix
Sandstone
Arenite
Jasper (Chert)
Silicon Dioxide (SiO2)
Sandstone (Quartz-rich)
Arenite (Quartz Arenite)
Sandstone
Arenite
Sandstone (Ferruginous)
Arenite (with iron oxide cement, Fe2O3)
Agate (Crazy Lace or Eye Agate)
Silicon Dioxide (SiO2)
Sandstone (with potential iron-oxide staining)
Arenite (primarily SiO2)
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Mineral and Rock Collection (Assorted)
Mixed collection including Quartz (SiO2), Jasper (SiO2 with impurities), Rose Quartz, and Aventurine
Gneiss
Gneiss
Gray Limestone Fragment
Limestone (CaCO3)
Limestone with Calcite Veining
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based with mineral cement)
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
Clear/White Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Sandstone
Arenite (Secondary classification based on grain size)
Sandstone Cobble
Arenite (primarily Quartz Arenite)
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
Chert (and Agate/Chalcedony)
Microcrystalline Quartz (SiO2)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement