Ironstone Concretion (Siderite Nodules)
Siderite (FeCO3) in Mudstone or Sandstone matrix
Category
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
Ironstone Concretion (Siderite Nodules)
Siderite (FeCO3) in Mudstone or Sandstone matrix
Banded Flint (Polished Stripe Flint)
Silicon Dioxide (SiO2) - variety of Chert
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with goethite or iron oxide inclusions
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
Yellow Jasper
Silicon Dioxide (SiO2) with goethite or iron oxide inclusions
Dyed Howlite (Dyed Red)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Yellow Calcite
Calcium Carbonate (CaCO3)
Optical Calcite (Iceland Spar)
Calcite (CaCO3)
Garnet (Almandine)
Almandine, Fe3Al2Si3O12
Specular Hematite with Quartz and Limonite
Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)
Native Gold (in earring form)
Gold (Au)
Calcite
Calcium Carbonate (CaCO3)
Specular Hematite (Polished Sphere)
Hematite (Alpha Fe2O3)
Hematite
Hematite, Iron(III) oxide (Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)
Agate
Banded Chalcedony (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Sandstone
Arenite (primarily SiO2)
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Hag Stone
Perforated Sedimentary Rock
Sandstone
Arenite (SiO2 based)
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Fossil Shark Tooth
Carcharodon or Carcharias fossil (Vertebrate Fossil)
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Gneiss (specifically Granite Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
Dinosaur Fossil (Skull)
Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Bauxite (Pisolitic Bauxite)
Bauxite (mixture of Hydrous Aluminum Oxides)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Arenite (Sedimentary Rock)
Yellow Jasper
Chalcedony (SiO2) with Goethite/Iron oxide inclusions
Ironstone Concretion (Moqui Marble type)
Iron oxide concretion (Goethite/Hematite and Sandstone)
Calcite with iron staining
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)