Limestone
Calcium Carbonate (CaCO3)
Category
Browse organic (sedimentary context) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Limonite-pseudomorph after Pyrite (Prophecy Stone)
Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Sandstone (Nut-stone / Cup-stone artifact)
Quartz Arenite / Worked Sedimentary Rock
Red Jasper (Mookaite style)
Silicon Dioxide (SiO2) with iron oxide impurities
Red Sandstone
Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
Zebra Jasper
Tetragonal Silicon Dioxide (Quartz) with impurities
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Yellow Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Yellow Jasper
Chalcedony (SiO2) with iron oxide inclusions
Chalcedony Geode / Agate Nodule
Cryptocrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Graywacke
Graywacke
Chert (Nodule)
Chert (variety of microcrystalline quartz, SiO2)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Ferruginous Sandstone (with Laterite)
Ferruginous Arenite (FeO(OH)·nH2O)
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Mica Schist
Mica Schist (Quartz-Mica Schist)
Pyrite
Pyrite (FeS₂)
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Red Jasper (River Siltstone)
Silicon Dioxide (SiO2) with iron oxide inclusions
Ironstone Concretion
Limonitic/Hematitic Concretion
Jasper with Iron Staining
Silicon Dioxide (SiO2) with impurities
Quartz Geode
Silicon Dioxide (SiO2)
Flint or chert flake
Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
Red Jasper
Opaque microcrystalline Quartz (SiO2 with Fe2O3 inclusions)
River Cobble (Conglomerate context)
Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Hematite
Iron(III) oxide (Fe2O3)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Leopard Skin Jasper
SiO2 (Microcrystalline Quartz with inclusions)
Quartz
Quartz (SiO2)
Ferruginous Conglomerate
Ferruginous Conglomerate (Clastic Sedimentary Rock)