Gneiss
Gneiss (High-grade regional metamorphic rock)
Category
Browse igneous or metamorphic (base stone); anthropogenic (decoration) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade regional metamorphic rock)
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
Orange Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
Moonstone
Adularia (orthoclase) or Albite (plagioclase), a potassium aluminum silicate of the feldspar group
White Topaz
Aluminum Silicate Fluoride Hydroxide, Al2SiO4(F,OH)2
Basalt
Basalt
Basalt
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Basalt
Basalt (High-iron/magnesium silicate rock)
Pink Granite
Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)
Basalt
Basalt (extrusive volcanic rock)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
Vesicular Basalt (Scoria)
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Basalt
Basalt (SiO2 percentage between 45% and 52%)
Garnet
Garnet Group (often Pyrope or Almandine); X3Y2(SiO4)3
Conglomerate
Conglomerate (Clastic sedimentary rock)
Sandstone
Arenite (primarily SiO2)
Sandstone with Tafoni Weathering
Arenite (SiO2 based)
Sandstone (with Manganese staining)
Arenite (composed primarily of SiO2)
Muscovite Schist
Muscovite (KAl2(AlSi3O10)(OH)2) in Schist
Stichtite in Serpentine (Atlantasite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Hematite
Iron(III) oxide (Fe2O3)
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (specifically as a lithic artifact/projectile point)
Chert (Silicon dioxide, SiO2)
Sandstone (Quartz-rich)
Sandstone (SiO2 dominated)
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Sapphire (Corundum)
Corundum (Al2O3)
Basalt
Basalt (Mafic volcanic rock)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Citrine (Quartz variant)
SiO2 (Silicon Dioxide)
Magnetite
Magnetite (Fe3O4)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartzite (river pebble) and Gabbro (crushed rock)
Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)
Blue Sapphire
Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)
Blue Calcite
Calcium Carbonate (CaCO3)