Red Sandstone
Arenite (Ferruginous Sandstone)
Category
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
Red Sandstone
Arenite (Ferruginous Sandstone)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Fossil Rugose Coral (Horn Coral)
Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)
Sandstone
Arenite (primarily Quartz, SiO2)
Sandstone Concretion
Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
African Turquoise (Jasper)
Silicon Dioxide (SiO2) - Macro-crystalline Quartz with inclusions
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Quartz (Milky/Clear)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Quartz (Milky/Chalcedony variety)
Silicon Dioxide (SiO2)
Bauxite
Alumina-rich rock (consisting of Gibbsite, Boehmite, and Diaspore)
Jasper
Cryptocrystalline Quartz (SiO2)
Banded Iron Formation (BIF)
Banded Iron Formation
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
Bauxite
Hydrated Aluminum Oxides (primarily Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Clear Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Schist
Mica Schist
Green Fluorite
Calcium Fluoride (CaF2)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Septarian Nodule (Septarian Dragon Stone)
Septarian concretion (composition: Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
Mookaite Jasper
Radiolarite (Silicon Dioxide, SiO2)
Jasper with Hematite Inclusions
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Jasper-Agate Breccia
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Calamites (Fossil)
Calamites sp. (Tracheophyta, Equisetopsida)
Gneiss (Metamorphic Rock)
Gneiss
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
Dyed Pink Agate Slice
Cryptocrystalline variety of Quartz (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO₂)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Rough Quartz
Quartz (Silicon Dioxide, SiO2)
Chalcedony
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Chalcedony (Desert Rose or Botryoidal Chalcedony)
Silicon Dioxide (SiO2)