Limonite / Goethite (Ironstone Nodule)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Category
Browse sedimentary mineral specimens identified by the Rock Identifier community.
Limonite / Goethite (Ironstone Nodule)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Ironstone Concretion / Chert Nodules
Iron-rich Sedimentary Concretion (Fe2O3 / SiO2 mix)
Sandstone with Iron Concretion
Arenite with Limonite/Goethite Concretion
Sandstone (with Iron Oxide)
Quartz Arenite / Ferruginous Sandstone (SiO2 with Fe2O3)
Weathered iron-rich sandstone or lateritic rock
Quartz-rich sandstone with iron-oxide/hydroxide cement; possible goethite-bearing laterite
Quartz Geode
Silicon Dioxide (SiO2)
Breccia
Sedimentary Breccia
Blue Apatite
Ca5(PO4)3(F,Cl,OH)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Quartz Pebble
Silicon Dioxide (SiO2)
Fossil Shell (Bivalve)
Class Bivalvia (fossilized)
Pink Granite Gneiss
Gneiss (High-grade metamorphic rock)
Pyrite
Iron Sulfide (FeS2)
Blue calcite (probable)
Calcite, calcium carbonate (CaCO₃)
Yellow Calcite
Calcium Carbonate (CaCO3)
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Quartz
Silicon Dioxide (SiO2)
Cleavable Calcite
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcium Carbonate (CaCO3)
Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Optical Calcite
Calcium Carbonate (CaCO3)
Geode or Concretion
Silica-filled nodule (likely SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Quartz Geode
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Yellow Calcite
Calcium Carbonate (CaCO3)
Foliated Metamorphic Rock (likely Gneiss or Schist)
Gneissic Metamorphic Rock
Limonite
Limonite (FeOO·nH2O)
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Hag Stone
Perforated sedimentary rock (typically sandstone or limestone)
Sandstone
Arenite (SiO2 composition primarily)
Limonite (Ironstone Concretion)
Limonite (FeO(OH)·nH2O)
Shark Tooth Fossil
Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)
Small weathered fossil or mineral fragment
Indeterminate; possibly fossilized shell, bone, or a pale carbonate mineral
Sandstone
Clastic Sedimentary Rock
River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
Worn River Pebble with Fossil Indentation
Sedimentary Rock with Fossil Infill
Quartz pebble
SiO2
Hematite
Iron(III) oxide (Fe2O3)