Quartz Geode
Crystalline Silicon Dioxide (SiO2) within a nodule
Category
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
Quartz Geode
Crystalline Silicon Dioxide (SiO2) within a nodule
Dalmatian Stone
Dalmatian Jasper (Aphanitic Igneous Rock with Arfvedsonite inclusions)
Sandstone (Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)
Quartz (SiO₂ - Silicon Dioxide)
Chert (specifically Flint)
Silicon Dioxide (SiO2)
Agate (Thunderegg segment)
Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (SiO2 + various cementing minerals)
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
Agate
Silicon Dioxide / Cryptocrystalline Quartz (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Pink Quartzite
Quartzite (SiO2 with iron oxide inclusions)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Clear Quartz
Silicon Dioxide (SiO2) / Rock Crystal
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Fe2O3 staining)
Quartzite pebble
Metamorphic Quartzite (primarily SiO2)
Quartzite (specifically a river-worn pebble)
Quartzite (primarily SiO2)
Quartz-veined Schist (or Metasandstone)
Metamorphic Rock with Quartz Veining (SiO2)
Banded Iron Formation (BIF)
Banded Iron Formation (Magnetite-Hematite-Chert)
Jasper River Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Red Jasper (River Siltstone)
Silicon Dioxide (SiO2) with iron oxide inclusions
Blue Chalcedony (Tumbled)
Silicon Dioxide (SiO2)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Red Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Sandstone (Ferruginous)
Arenite (with Iron Oxides)
Blue Agate (Dyed)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Pink Chalcedony (Agate/Jasper blend)
Silicon Dioxide (SiO₂)
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)
Jasper (Green)
Silicon Dioxide (SiO2) with impurities
Glauconitic Sandstone
Glauconitic Sandstone with high Glauconite concentration ((K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Sandstone
Arenite
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Sandstone (Red Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)
Quartzite (River Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)