Sandstone
Arenite (primarily SiO2)
Category
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Quartz (likely Clear Quartz or Rock Crystal)
Quartz (SiO2)
Basalt with Iron Oxidation
Amygdaloidal Basalt (silicate rock primarily plagioclase, pyroxene, and olivine)
Fluorite (Rainbow Fluorite)
Calcium Fluoride (CaF2)
Basalt
Basalt
Hematite
Iron(III) oxide (Fe2O3)
Bumblebee Jasper
Fossiliferous Volcanic Rock (composed of Calcium Carbonate, Manganese Oxides, and Arsenic Sulfides)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Basalt with Weathering Crust
Extrusive mafic volcanic rock
Basalt
Basalt (Mafic volcanic rock)
Quartz (beads)
SiO2 (Silicon Dioxide)
Opal
Hydrous silicon dioxide (SiO2·nH2O)
Basalt River Stone (Tumbled)
Basalt (Mafic Extrusive Igneous Rock)
Citrine
Citrine (Silicon Dioxide - SiO2)
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
Basalt with Quartz Veins
Vesicular or aphanitic Basalt with SiO2 (Quartz) intrusions
Smoky Quartz (with Hematite inclusions)
Silicon Dioxide (SiO2)
Yellow Ochre / Limonite
Limonite (inter-mixed iron oxides and hydroxides, primarily FeO(OH)·nH2O)
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
Obsidian
Vitreous volcanic silicate (70-75% SiO2)
Serpentinite
Serpentinite (composed largely of serpentine group minerals including Antigorite, Lizardite, or Chrysotile)
Pumice
Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)
Granite
Granite (Felsic Plutonic Rock)
Calcite
Calcite (Mineral; CaCO₃)
Sandstone
Arenite (primarily SiO2)
Quartzite (Milky)
Metamorphic rock predominantly composed of Quartz (SiO2)
Seraphinite
Clinochlore (a variety of the chlorite group)
Ferruginous Sandstone (Gritstone)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3 and FeO(OH))
Smoky Quartz
Smoky Quartz (SiO2 - Silicon Dioxide with aluminum impurities)
Citrine
Citrine (Silicon Dioxide, SiO2)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
Basalt Pebble with Epidote/Olivine
Vitreous Basalt (SiO2 with Ca/Mg/Fe silicates)
Basalt
Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Granite
Granite (Felsic Plutonic Rock)
Sandstone (likely Iron-rich or Arkosic)
Arenite (SiO2 with FeO(OH) or Fe2O3 staining)
Serpentine
Serpentine-group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Gold Nugget
Native Gold (Au)
Crystal Quartz Beads (likely Clear Quartz)
Quartz (SiO₂)