Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
Category
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
Gneiss
Gneiss
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Banded Calcite or Travertine
Calcium Carbonate (CaCO3)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Petrified Wood
Silicified Wood (SiO2)
Greenstone
Metamorphosed Mafic Igneous Rock
Sandstone
Arenite (primarily composed of SiO2)
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
River Quartzite Siltstone
Quartz-rich Meta-siltstone (SiO2 dominated)
Clear Quartz
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Fluorite
Calcium Fluoride (CaF2)
Fluorite
Fluorite (CaF₂)
Gneiss
Gneiss
Gneiss
Gneiss
Sandstone (Micaceous)
Arenite (composed primarily of SiO2)
Pyrite
Pyrite (FeS2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite inclusions
Citrine
SiO2 (Silicon Dioxide)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Agate
Silicon dioxide (SiO2)
Sphalerite
Zinc Sulfide (Zn,Fe)S
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Jasper (likely Polychrome or Mookaite variants)
Silicon Dioxide (SiO2) with iron oxide and hydroxide inclusions
Hematite
Iron(III) oxide (Fe2O3)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Agate
Silicon Dioxide (SiO2) - variety: Chalcedony
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Banded Agate (specifically Carnelian Agate slice)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
Blue Caribbean Calite
Calcium Carbonate (CaCO3) with trace Aragonite
Fancy Jasper
Silicon Dioxide (SiO2) with impurities