Fossil / Permineralized Bone
Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)
Category
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Fossil / Permineralized Bone
Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)
Ferruginous Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)
Gneiss
Gneiss
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Fluorite with Quartz coating
Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Sandstone (likely Arkosic or Lithic Sandstone)
Clastic Sedimentary Rock (SiO2 with assorted minerals)
Sandstone
Arenite (primarily SiO2)
Pyrite
Iron Sulfide (FeS2)
Sandstone (Micaceous)
Arenite (composed primarily of SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Magnetite
Magnetite (Fe3O4)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Ironstone (likely Limonite or Goethite nodule)
Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
Limonite with Hematite
Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
Bornite
Bornite (Cu5FeS4)
Sandstone
Arenite (SiO2 principal)
Sandstone
Arenite
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)
Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (composed primarily of SiO2)
Paper (Cellulose)
Cellulose (C6H10O5)n
Breciated Limestone with Calcite Veins
Sedimentary Breccia (CaCO3)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Yellow Quartzite
Quartzite (SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Shale
Shale (fine-grained clastic sedimentary rock)
Shale
Shale (clastic sedimentary rock)
Sandstone (Banded)
Clastic sedimentary rock (primarily SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Quartz Geode
Silicon Dioxide (SiO2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Sulfur (on Matrix)
Native Sulfur (S8)
Shale
Fissile Mudstone
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities