Chert (Smooth River Pebble)
Silicon Dioxide (SiO2)
Category
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
Chert (Smooth River Pebble)
Silicon Dioxide (SiO2)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
Sandstone
Arenite (SiO2 dominant)
Granodiorite with Quartz Veining
Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins
Gneiss
Gneiss (High-grade Metamorphic Rock)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Druzy Quartz (on Geode Fragment)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (composed primarily of SiO2)
Jasper-Agate Breccia
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartzite River Rock
Quartzite (primarily SiO2)
Biotite Schist
Biotite Schist
Jasper (Iron-stained Quartzite/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz pebble
Silicon dioxide (SiO2)
Ceramic or Polished Stone Heart (Anthropogenic Material)
Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
Banded Agate (Dyed Purple)
Agate (Variety of Chalcedony/Quartz), SiO2
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Chalcedony
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Quartz Druzy on Basalt
Silicon Dioxide (SiO2) on Mafic Volcanic Rock
Banded Iron Formation (Jaspilite)
Banded Iron Formation (BIF); predominantly Hematite (Fe2O3) and Magnetite (Fe3O4) with Chert/Jasper (SiO2)
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Laterite (iron-rich nodule, possibly Bauxite as a subtype)
Laterite (composed of various minerals including goethite, hematite, gibbsite, etc.)
Pyrite (on Quartz/Host Rock)
Iron Sulfide (FeS₂)
Milky Quartz
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
River Stone (likely Siltstone or fine-grained Basalt)
Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)
Jasper (specifically a banded or dark variety)
Silicon Dioxide (SiO2) with impurities
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Banded Sandstone
Arenite (composed primarily of Quartz: SiO2)
Ferruginous Sandstone (with ripple marks)
Arenite with Iron-Oxide (Fe2O3) cement
Jasper (Iron-stained)
Silicon Dioxide (SiO2) with iron oxide inclusions
Limonitic Quartzite
Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Fossil Coral
Coral Limestone (a type of biogenic sedimentary rock)
Jasper Cross
Silicon Dioxide (SiO2) with iron oxide impurities
Quartzite River Stone
Metamorphosed Quartz-rich Sandstone (SiO2)
Banded Agate (Crazy Lace/Mexican Agate Variety)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)