Shungite
Non-crystalline carbon (high-carbon metamorphic rock)
metamorphic
Category
Sedimentary (Formed From Silica Deposits)
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Chert (Flint)
Chert (SiO2)
sedimentary
Limonite
Limonite (FeOO·nH2O)
mineral
Glauconite
(K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Carnelian
Carnelian (Silicon Dioxide - SiO2)
mineral
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Ocean Jasper (Orbicular Jasper)
Orbicular Rhyolite (SiO2)
igneous
Yellow Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Fossiliferous Limestone (Crinoidal Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
sedimentary
Chalcedony (Botryoidal/Tumbled Agate)
Silicon Dioxide (SiO2)
mineral
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Sandstone (Weathered)
Arenite (primarily SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Limonitic Sandstone (Stained Sandstone)
Clastic Sedimentary Rock with Iron Oxide (Limonite/Goethite) staining
sedimentary
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite
sedimentary
Chert (Nodular)
Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Aventurine
Quartz (SiO2) with inclusions of Fuchsite
mineral
Amethyst Geode
Amethyst (Silicon Dioxide, SiO2)
mineral
Chalcedony (Agate/Carnelian type)
Silicon Dioxide (SiO2)
mineral
Coquina
Coquina (Bioclastic Limestone)
sedimentary
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Pyrite (on host rock/ore)
Iron Sulfide (FeS2)
mineral
Banded Agate
Silicon Dioxide (SiO2)
mineral
Ironstone (likely Ferruginous Siltstone/Sandstone)
Ferruginous sedimentary rock (FeOx-rich clastic)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Coquina / Fossiliferous Limestone
Coquina (composed primarily of Calcium Carbonate / CaCO3)
sedimentary
Quartz River Pebbles
Silicon Dioxide (SiO2)
sedimentary
Rock Crystal Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Geode (Quartz)
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Metamorphic Quartzite (SiO2)
metamorphic
Turquoise (set in silver jewelry)
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
mineral