Pyrite
Iron Sulfide (FeS2)
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Pyrite
Iron Sulfide (FeS2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Sandstone
Arenite (composed primarily of SiO2)
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)
Schist
Mica Schist
Sandstone (Red)
Arenite (primarily Quartz, SiO2, with Iron Oxide cement)
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
Ferruginous Sandstone (Red Sandstone)
Arenite with Hematite/Limonite cement
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Banded Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (SiO2 with Iron Oxide impurities)
Red Sandstone
Arenite (Ferruginous Sandstone)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Quartz Pebble
Silicon Dioxide (SiO2)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Siltstone
Siltstone (primarily composed of SiO2 with various clay minerals)
Sandstone
Arenite (composed primarily of SiO2)
Jasper with Manganese Dendrites
Silicon Dioxide (SiO2) with Oxide Mineral Inclusions
Brecciated Chert
Sedimentary Chert (SiO2) with Calc-Silicate mineralization
Jasper (var. Ocean or Polychrome Jasper)
Silicon Dioxide (SiO2) with iron and mineral inclusions
Yellow Ocher (Limonite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Rutilated Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions
Quartzite Pebble
Quartzite (primarily SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Apatite
Apatite (Ca5(PO4)3(F,Cl,OH))
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rough Diamond
Diamond (pure Carbon, C)
Raw Diamond
Carbon (C)
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Corundum (Ruby Variety)
Corundum (Al2O3)
Schist
Mica Schist
Granite
Phaneritic Igneous Rock (Granite)
Amygdaloidal Basalt with Epidote
Vesicular Basalt with secondary Epidote/Quartz mineral infill
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Quartz
Silicon Dioxide (SiO2)
Quartzite River Rock with Dendrites
Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions