Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
Category
Browse metamorphic or igneous (context dependent) specimens identified by the Rock Identifier community.
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
Limonite-pseudomorph after Pyrite (Prophecy Stone)
Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Yellow Jasper
Chalcedony (SiO2) with iron oxide inclusions
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Cobaltian Calcite (Cobaltoan Calcite)
Cobalt-bearing Calcite (Ca,Co)CO3
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Green Moonstone (Garnierite)
Nickel-bearing Magnesium Silicate (often a mix of Serpentine and Talc/Chlorite groups)
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Graywacke
Graywacke
Baroque Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Zebra Jasper
Tetragonal Silicon Dioxide (Quartz) with impurities
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
Tiger's Eye (often misinterpreted as Gold Ore in this context)
Pseudomorph of Quartz after Crocidolite (SiO2)
Chert Nodule
Microcrystalline Silica (SiO2)
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Garnet
Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)
Ferruginous Sandstone (Gritstone)
Clastic sedimentary rock with iron-rich cement (FeO(OH)·nH2O)
Slag
Anthropogenic Vitrophyre (Iron or Smelting Slag)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Gold
Gold (Native Au)
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
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Chert (Smoky variety)
Microcrystalline Quartz (SiO2)
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
Black Onyx
Black Chalcedony (SiO2)
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
Gneiss
Gneiss (pronounced 'nice')
Gold (Processed)
Gold (Au)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)