Hematite
Iron(III) oxide (Fe2O3)
mineral
Category
Sedimentary (Secondary Mineral Formation)
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
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Ferruginous Quartz
Silicon Dioxide with Hematite/Limonite inclusions (SiO2 + Fe2O3)
mineral
Hematite (Iron Ore)
Hematite (Fe2O3)
mineral
Fluorite Tower
Fluorite (Calcium Fluoride - CaF2)
mineral
Hematite / Goethite (Iron Ore)
Iron Oxide (Fe2O3 / FeO(OH))
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Limonite (Goethite/Ironstone)
Hydrated iron oxide-hydroxide, approximately FeO(OH)·nH2O
mineral
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, FeO(OH)·nH2O)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Sandstone
Arenite (primary component SiO2)
sedimentary
Quartz Geode / Druzy Quartz Node
Silicon Dioxide (SiO2)
sedimentary
Hematite
Iron(III) oxide (Fe2O3)
mineral
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
sedimentary
Limonite (Gozzany Iron)
Limonite (FeO(OH)·nH2O)
mineral
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)
Sedimentary
Gold Flake
Native Gold (Au)
mineral
Hematite (Nodular or Botryoidal)
Iron(III) oxide (Fe2O3)
mineral
Quartz Geode
Quartz (Silicon Dioxide, SiO2) Geode
sedimentary
River Pebble (likely Quartzite or Chert)
Sedimentary Clast (Silicon Dioxide dominant)
sedimentary
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper Agate
Chalcedony (Silicon Dioxide - SiO2)
mineral
Native Sulfur
Sulfur (S8)
mineral
Okenite
Okenite, Ca3Si6O15·6H2O
mineral
Weathered copper-bearing rock, possibly chrysocolla-bearing quartz or host rock
Indeterminate from the photo; possible chrysocolla (hydrated copper silicate) with quartz or other host minerals
mineral
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
mineral
Tumbled blue-green stone, likely chrysocolla-bearing material
Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; identification is provisional from the photograph
mineral
Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Geode with Iron-Stained Quartz/Calcite
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix
sedimentary
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Agate Geode
Silicon Dioxide (SiO2)
sedimentary
Green Jasper
Microcrystalline Quartz (Chalcedony), SiO2
sedimentary
Psilomelane (Black Hematite/Manganese Ore)
Barium Manganese Oxide (Formula: BaMn9O18(OH)4)
mineral
Agate (Water-Worn Pebble)
Silicon Dioxide (SiO2) - Chalcedony
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Agate Nodule (partially vuggy Quartz)
Silicon Dioxide (SiO2)
Mineral/Sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3) - Sparry Limestone
sedimentary
Quartz crystal cluster
Quartz, silicon dioxide (SiO₂), likely milky or partially included rock crystal
mineral
Botryoidal Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
mineral
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Quartzite with Quartz Vein
Quartzite (SiO2)
metamorphic