Sandstone
Arenite (primarily SiO2)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Sandstone (Quartzose)
Arenite (SiO2 based)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Sandstone
Arenite (Siliclastic sedimentary rock), SiO2 + various minerals
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Arkosic Sandstone (or Conglomeritic Sandstone fragment)
Arkose (rich in feldspar)
Banded Gneiss
Gneiss
Sandstone (Ferruginous)
Arenite (Fe-rich)
Asphalt (Bituminous Slate/Sandstone)
Asphaltum / Bituminous Rock
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
Basalt with Weathered Rind
Basalt (Aphanitic Mafic Igneous Rock)
Sandstone (Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Gneiss
High-grade Metamorphic Gneiss
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Green Aventurine
Silicon dioxide (SiO2) with fuchsite inclusions
Breciated Chert
Brecciated Chert (Microcrystalline Quartz, SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Mixed Tumbled Stones Collection
Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Plume Agate
Silicon Dioxide (SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
Travertine
Calcareous Tufa (CaCO3)
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
Chert (Nodule)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Red Sandstone
Arenite (Ferruginous Sandstone)
Ironstone (Limonitic Sandstone)
Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)
Oolitic Limestone (Egg Stone)
Oolite (Chemical sedimentary rock, primarily CaCO3)
Sandstone (Quartzite-rich Pebble)
Arenite (primarily SiO2)
Breciated Limestone with Calcite Veins
Sedimentary Breccia (CaCO3)