Basalt with Vesicular Texture (Beach Cobble)
Vesicular Basalt (Aphanitic Igneous Rock)
Category
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Basalt with Vesicular Texture (Beach Cobble)
Vesicular Basalt (Aphanitic Igneous Rock)
Pyrite with Limonite/Goethite Alteration (Pseudomorph)
Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartzite
Quartzite (SiO2)
Milky Quartz Pebble
Silicon dioxide (SiO2)
Quartz (small fragment)
Silicon Dioxide (SiO2)
Quartz (Quartzite fragment)
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Green Quartzite
Metamorphic Quartzite (often colored by chromium-bearing minerals or fuchsite)
Granite
Phaneritic Plutonic Felsic Rock
Chert (Jasper/Flint var.)
Silicon Dioxide (SiO2)
Chert (Chert / Flint Variety)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Flint / Chert
Silicon dioxide (SiO2)
Pyrite
Iron Disulfide (FeS2)
Clear Quartz
Silicon Dioxide (SiO2)
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Limestone Pebble
Calcium Carbonate (CaCO3)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Pyrite (Fool's Gold)
Iron Pyrite (FeS2)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Rounded gray stone, likely slate or fine-grained sandstone
Probable slate (low-grade metamorphosed shale) or lithic sandstone; exact identification requires testing
Basalt with Fusion Crust (Meteorite-like appearance)
Vesicular Basalt
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Chert (Jasper/Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Conical fossil shell or shell fragment
Likely a gastropod shell fragment; exact taxon indeterminate from the image
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Smoky Quartz
Silicon Dioxide (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
Likely metallic sulfide mineral fragment
Possibly galena (PbS) or pyrite (FeS₂); identification is uncertain from the photograph
Sandstone
Arenite (with iron oxide cement)
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Coquina
Bioclastic Limestone (Coquina)
Sandstone Cobble with Liesegang Rings
Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)
Granite (probable)
Granite; chiefly quartz, feldspar, and mica
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)