Chert (often called Flint or Jasper based on color)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Rock (Likely Sedimentary)
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Sandstone
Arenite
sedimentary
Sandstone (likely Quartzite-grade)
Arenite (primarily SiO2)
sedimentary
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Mineral
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
sedimentary
Granite Pebble (Salt and Pepper Granite)
Felsic Intrusive Igneous Rock (Granite)
igneous
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
mineral
Goldstone (Red)
Aventurine Glass
Man-made material (Simulated Mineral)
River Pebble (Greywacke or Basaltic)
Massive Greywacke or Basaltic Andesite
sedimentary or igneous
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
sedimentary
Sandstone (Iron-stained)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Siltstone with iron staining
Siltstone (primarily SiO2 with FeO(OH) coatings)
sedimentary
Tiger's Iron
Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)
metamorphic
Sandstone
Arenite (SiO2 based)
sedimentary
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
igneous
Dalmation Stone (often called Dalmatian Jasper)
Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite
igneous
Sandstone
Arenite (SiO2 primarily)
sedimentary
Epidote (likely Pistacite in Epidosite rock)
Epidote: Ca2(Al,Fe)3(SiO4)3(OH)
metamorphic
Quartzite (River Cobble)
Metamorphic Rock (composed predominantly of SiO2)
metamorphic
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (SiO2 principal)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Mineral
Jasper and Ironstone (likely Jasperized Ironstone)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
sedimentary
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
sedimentary
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
mineral
Sandstone (lithic/greywacke variant)
Clastic sedimentary rock (primarily SiO2 with rock fragments)
sedimentary
Quartzite Pebble (River Rock)
Quartzite (SiO2)
metamorphic
Portable Ceramic Space Heater
Polished Acrylonitrile Butadiene Styrene (ABS) Plastic with Ceramic Heating Elements
not a rock (synthetic/industrial object)
Fossiliferous Chert with Brachiopod Impression
Chert (SiO2) containing Brachiopoda fossil remains
sedimentary
Granite
Granite (a felsic intrusive igneous rock)
igneous
Granular Sandstone
Arenite (variable composition, primarily SiO2)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary