Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Category
Browse anthropogenic specimen (man made) specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Diamond (set in Gold)
Carbon (C)
Diamond (appearing in jewelry)
Diamond (pure Carbon, C)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2)
White Jade (Nephrite)
Nephrite, Ca2(Mg,Fe)5Si8O22(OH)2
Sandstone concretion (Ironstone-stained)
Arenite with Limonite/Hematite staining (Silica-based with Iron Oxides)
Quartz Druze on Matrix (Geode Fragment)
Quartz (Silicon Dioxide, SiO2)
Specular Hematite with Quartz and Limonite
Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)
Gold in Quartz
Hydrothermal Quartz with Native Gold (SiO2 with Au)
Sedimentary Sandstone (Sandstone Slab)
Arenite (SiO2 with Fe2O3 staining)
Granite
Intrusive igneous rock (high SiO2)
Painted Pet Rock (Quartzite/Sandstone base)
Silicon Dioxide (SiO2) with anthropomorphic acrylic embellishments
Agate with Quartz Druzy
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz Pebble (often referred to as 'Sea Glass' or 'River Stone' when worn smooth)
Silicon Dioxide (SiO2)
Iron Slag
Vitreous glassy waste (Fe-Si-Al-Ca compounds)
Chert (or possibly Flint)
Chert (variant: Flint)
Quartzite
Quartzite (primarily SiO2)
Quartzite with Iron inclusions
Metamorphosed Sandstone (SiO2 with Fe2O3)
Pyrite in Matrix (likely Quartz or Schist matrix)
Iron Sulfide (FeS2)
Schorl (Black Tourmaline) in Quartz and Feldspar
NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)
Chert (Pink Jasper)
Microcrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Ferruginous Sandstone
Clastic Sedimentary Rock (Iron-rich)
Quartz Vein in Siltstone
SiO2 (Quartz) on clastic sedimentary matrix
Fossiliferous Limestone
Biogenic Calcium Carbonate (CaCO3)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar intrusive rock)
Fossilized Brachiopod/Bivalve in Limestone
Brachiopoda or Bivalvia fossil in Calcite/Limestone (CaCO3)
Tourmalinated Quartz
Silicon Dioxide (SiO2) with Schorl inclusions (NaFe2+3Al6(BO3)3Si6O18(OH)4)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Carnelian Agate Nodule
Silicon Dioxide (SiO2) - Carnelian Chalcedony
Quartz / Quartz Geode fragment
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Tiger's Eye (likely Hawk's Eye variant)
Pseudomorph of Quartz after Crocidolite (SiO2)
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Sunstone
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
Quartzite River Rock
Quartzite (primarily SiO2)