Limonite Concretion
Goethite-rich Concretion (FeO(OH))
Category
Browse sedimentary rock specimens identified by the Rock Identifier community.
Limonite Concretion
Goethite-rich Concretion (FeO(OH))
Chert Nodule (Flint)
Chert (Cryptocrystalline Silica - SiO2)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Carnelian (Agate)
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Quartz Geode
Silicon Dioxide (SiO2)
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
Arkosic Sandstone (or Conglomeritic Sandstone fragment)
Arkose (rich in feldspar)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Chalcedony (SiO2 with iron oxide impurities)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron oxide inclusions
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Quartz Veined Rock (Likely Graywacke or Quartzite)
Silicon Dioxide (SiO2) veins in Metasedimentary matrix
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Smoky Quartz and Chalcedony Geode Fragment
Silicon Dioxide (SiO2)
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with iron oxide and other mineral impurities
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Agate variety)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Chert / Microcrystalline Quartz (SiO2)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
White Onyx (Marble Onyx)
Calcite (CaCO3) - Banded Calcium Carbonate
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Yellow or River Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Slate
Slate (Metamorphic Rock)
Quartz Geode in Sedimentary Matrix
Silicon Dioxide (SiO2) within a limestone/dolostone host
Black Opal
Hydrated Silica (SiO2·nH2O)
Geode (Quartz)
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Geode (unopened)
Silica-filled Concretion (SiO2)
Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)