Banded Iron Formation (BIF) / Iron Ore
Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)
sedimentary
Category
Sedimentary (Cryptocrystalline Silica)
Browse sedimentary (cryptocrystalline silica) specimens identified by the Rock Identifier community.
Sandstone
Arenite
sedimentary
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
sedimentary
Botryoidal Chalcedony (Desert Rose / Agate)
Silicon Dioxide (SiO₂)
Mineral variant
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Banded Iron Formation (BIF)
Magnetite-hematite-chert formation
sedimentary
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with high iron inclusion
sedimentary
Sandstone
Arenite (Clastic Sedimentary Rock)
sedimentary
Sandstone (with prominent jointing/fractures)
Arenite (composed primarily of SiO2)
sedimentary
Granular Sandstone
Arenite (variable composition, primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (likely Red/Brown Sandstone)
Arenite (SiO2 based)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
sedimentary
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
sedimentary
Red Jasper
Argillaceous microcrystalline quartz (SiO2 with Fe2O3 inclusions)
sedimentary
Red Jasper (Brecciated or Mottled)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
mineral
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
metamorphic and mineral
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Mineral
Carnelian
Silicon dioxide (SiO2) with iron oxide impurities
mineral
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
mineral
Carnelian (a variety of Chalcedony)
SiO2 (Silicon Dioxide) primarily colored by iron oxide (Hematite)
mineral
Red Jasper (Brecchiated Jasper)
Silicon Dioxide (SiO2) with Hematite impurities
Sedimentary / Mineral
Red Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)
Mineral (variety of Chalcedony/Quartz)
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Red Carnelian
Carnelian (Silicon Dioxide - SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix
Metamorphic or Igneous (context dependent)
Sandstone
Arenite (mostly SiO2)
sedimentary
Chert / River Pebble
Silicon Dioxide (SiO2)
sedimentary
Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)