Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Category
Sedimentary Rock (Altered)
Browse sedimentary rock (altered) specimens identified by the Rock Identifier community.
Banded Gneiss
Gneiss (Metamorphic high-grade, predominantly SiO2, Al2O3, K2O, Na2O)
metamorphic
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
mineral
Quartz Geode (with Agate banding)
Silicon Dioxide (SiO2)
Sedimentary or Igneous (secondary formation)
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
sedimentary
Red Sandstone
Arenite (high iron oxide content)
sedimentary
Jasper and Chert Conglomerate
Ferruginous Microcrystalline Quartz (SiO2)
sedimentary
Laterite
Laterite (Ferricrete)
sedimentary
Breccia
Clastic Breccia (General mineral composition depends on fragments, often SiO2 or CaCO3)
sedimentary
Red Sandstone
Arenite (Fe2O3-rich)
sedimentary
Sandstone with Liesegang Rings
Arenite with secondary Iron oxide (Limonite/Goethite) precipitation
sedimentary
Chert Pebble
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Greywacke (River Slikenside)
Greywacke (Lithic Sandstone)
sedimentary
Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Sedimentary
Druzy Quartz (on Quartzite or Chert)
Silicon Dioxide (SiO2)
mineral
Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
sedimentary
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
sedimentary
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Chert (Pink Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (specifically Cross-bedded Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Jasper (Red/Brown Variety)
Jasper (Silicon Dioxide, SiO2 plus Iron Oxide impurities)
sedimentary
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
sedimentary
Jasper
Silicon dioxide (SiO2) with iron impurities
sedimentary
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
Bumble Bee Jasper
Calcite-bearing Volcanic Tuff (not a true Jasper)
sedimentary
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
sedimentary
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
sedimentary
Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
sedimentary
Banded Iron Formation (BIF)
Banded Iron Formation
Sedimentary
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
metamorphic
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Mineral, specifically a variety of Quartz
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Ferruginous Sandstone
Sandstone, Iron-rich
sedimentary
Dendritic Siltstone (or Mudstone)
Siltstone with Manganese Oxide dendrites
sedimentary
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
sedimentary (fossilized organic remain)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Chert (specifically Yellow Jasper)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Mookaite Jasper
Silicified Radiolarite (Silicon Dioxide: SiO2)
sedimentary