Tumbled banded metamorphic stone
Likely banded gneiss or migmatitic gneiss; exact identification requires testing
Category
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
Tumbled banded metamorphic stone
Likely banded gneiss or migmatitic gneiss; exact identification requires testing
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Sandstone
Sandstone (SiO2 dominant)
Septarian Nodule (Pebble)
Septarian concretion (composition: CaCO3, calcite, aragonite, and clay/mudstone)
Blue calcite (likely)
Calcite, CaCO₃
Sandstone
Arenite (SiO2 dominant)
Pink Granite
Granite (Felsic Plutonic Rock)
Tumbled citrine quartz (likely heat-treated amethyst)
Quartz, SiO₂; crystalline variety citrine
Jasper and Quartz Breccia
Silicified Breccia / Microcrystalline Quartz
Chert (with Limestone/Dolomite host)
Microcrystalline Quartz (SiO2)
Amethyst (likely rough or cleaved fragment)
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
Amethyst-bearing quartz cluster
Quartz, SiO₂; purple coloration from irradiation and trace iron
Clear Quartz / Diamond (untested)
Silicon Dioxide (SiO2) or Carbon (C)
Chalcedony (Agate/Carnelian variety)
Cryptocrystalline Quartz (SiO2)
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Blue Aragonite
Aragonite (Calcium Carbonate, CaCO3)
Banded Calcite (Mexican Onyx)
Calcite (CaCO3)
Sandstone
Clastic Sedimentary Rock
Quartz Sand/Gravel
Silicon Dioxide (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (with Calcite or Silica veins)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (specifically Quartz Arenite)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite (primarily SiO2)
Polished labradorite
Labradorite, plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Amazonite
Microcline (var. Amazonite) - KAlSi3O8
Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Ferruginous Quartz
Iron-stained Quartz (Silicon Dioxide, SiO2 with Fe2O3 inclusions)
Chlorastrolite (Greenstone)
Chlorastrolite (variety of Pumpellyite) - Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2 · H2O
Sandstone
Arenite (SiO2 primarily)
Green aventurine quartz sphere
Quartz, SiO₂, with fuchsite or other green mica inclusions
Shark Tooth Fossil
Carcharodon / Otodus fossilized tooth (Calcium Phosphate / Hydroxyapatite)
Granite
Intrusive Igneous Rock
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
Sandstone
Arenite
Obsidian with Slate/Tuff
Volcanic glass (SiO2) with associated pyroclastic rock
Basalt with Epidote (Greenstone)
Epidote-bearing Metabasalt
Polished green-and-white stone, likely serpentine or nephrite jade
Serpentine-group minerals, commonly antigorite/lizardite; possible nephrite (interlocking actinolite–tremolite)
Honey-colored chalcedony (likely carnelian)
Microcrystalline quartz, SiO₂; orange chalcedony colored by iron oxides