Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Category
Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)
Zircon
Zirconium Silicate (ZrSiO₄)
Blue Quartz (Dumortierite Quartz)
Silicon Dioxide (SiO2) with inclusions of Dumortierite (Al7BO3(SiO4)3O3)
Quartzite
Quartzite (SiO2-rich metamorphic rock)
Chert
Microcrystalline Quartz (SiO2)
Citrine (Yellow Quartz)
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Quartzite River Stone
Metamorphic Quartzite (primarily SiO2)
Selenite (gypsum)
Gypsum, CaSO₄·2H₂O; variety: selenite
Gypsum crystal cluster (selenite/ satin-spar variety)
Gypsum — calcium sulfate dihydrate, CaSO₄·2H₂O
Quartz
Silicon Dioxide (SiO2)
Druzy Quartz Geode (Oco or Moroccan variety)
Silicon Dioxide (SiO2)
Quartz Druzy Geode
Silicon Dioxide (SiO2)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geode
Chert (Flint)
Microcrystalline quartz (SiO2)
Bauxite (Aluminum Ore)
Hydrated aluminum oxides, primarily Al(OH)3, AlO(OH)
Blue Quartzite
Metamorphic Rock (rich in Quartz, SiO2 with inclusions of Dumortierite or Magnesio-riebeckite)
Quartzite (Orthoquartzite)
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2 silicon dioxide)
Lapis Lazuli
Lapis lazuli (Complex silicate mixture including Lazurite, Calcite, and Pyrite)
Lapis Lazuli
Lapis Lazuli (Complex aggregate of Lazurite, Calcite, and Pyrite)
Lapis Lazuli
Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)
Jasper
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Jasper and Quartz conglomerate
Silicon Dioxide (SiO2) with iron oxide impurities
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Jasper
Opaque Cryptocrystalline Quartz (SiO2)
Jasper with Hematite Inclusions
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Dendritic Agate
Chalcedony (SiO2) with manganese/iron oxide inclusions
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Limestone
Calcium Carbonate (CaCO3)
Quartz Pebble
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Flint Pebble
Sedimentary cryptocrystalline quartz (SiO2)
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
Fossiliferous Limestone
Carbonate sedimentary rock (CaCO3) with bioclasts